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# jfmengels/lodash-fp-documentation.md

Last active Apr 15, 2021
Generated docs for Lodash/fp. Help make them better at https://github.com/jfmengels/lodash-fp-docs

# lodashv4.17.20

## `“Array” Methods`

### `_.chunk(size, array)`

Creates an array of elements split into groups the length of `size`. If `array` can't be split evenly, the final chunk will be the remaining elements.

3.0.0

#### Arguments

1. `size` (number): The length of each chunk
2. `array` (Array): The array to process.

#### Returns

(Array): Returns the new array of chunks.

#### Example

```_.chunk(2, ['a', 'b', 'c', 'd']);
// => [['a', 'b'], ['c', 'd']]

_.chunk(3, ['a', 'b', 'c', 'd']);
// => [['a', 'b', 'c'], ['d']]```

### `_.compact(array)`

Creates an array with all falsey values removed. The values `false`, `null`, `0`, `""`, `undefined`, and `NaN` are falsey.

0.1.0

#### Arguments

1. `array` (Array): The array to compact.

#### Returns

(Array): Returns the new array of filtered values.

#### Example

```_.compact([0, 1, false, 2, '', 3]);
// => [1, 2, 3]```

### `_.concat(array, values)`

Creates a new array concatenating `array` with any additional arrays and/or values.

4.0.0

#### Arguments

1. `array` (Array): The array to concatenate.
2. `values` (*|*[]): The values to concatenate.

#### Returns

(Array): Returns the new concatenated array.

#### Example

```var array = [1];
var other = _.concat(array, [2, [3], [[4]]]);

// => [1, 2, 3, [4]]

// => [1]```

### `_.difference(array, values)`

Creates an array of `array` values not included in the other given arrays using `SameValueZero` for equality comparisons. The order and references of result values are determined by the first array.

Note: Unlike `_.pullAll`, this method returns a new array.

0.1.0

#### Arguments

1. `array` (Array): The array to inspect.
2. `values` (Array|Array[]): The values to exclude.

#### Returns

(Array): Returns the new array of filtered values.

#### Example

```_.difference([2, 1], [2, 3]);
// => [1]```

### `_.differenceBy(iteratee, array, values)`

This method is like `_.difference` except that it accepts `iteratee` which is invoked for each element of `array` and `values` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument:
(value).

Note: Unlike `_.pullAllBy`, this method returns a new array.

4.0.0

#### Arguments

1. `iteratee` (Function): The iteratee invoked per element.
2. `array` (Array): The array to inspect.
3. `values` (Array|Array[]): The values to exclude.

#### Returns

(Array): Returns the new array of filtered values.

#### Example

```_.differenceBy(Math.floor, [2.1, 1.2], [2.3, 3.4]);
// => [1.2]

// The `_.property` iteratee shorthand.
_.differenceBy('x', [{ 'x': 2 }, { 'x': 1 }], [{ 'x': 1 }]);
// => [{ 'x': 2 }]```

### `_.differenceWith(comparator, array, values)`

This method is like `_.difference` except that it accepts `comparator` which is invoked to compare elements of `array` to `values`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal).

Note: Unlike `_.pullAllWith`, this method returns a new array.

4.0.0

#### Arguments

1. `comparator` (Function): The comparator invoked per element.
2. `array` (Array): The array to inspect.
3. `values` (Array|Array[]): The values to exclude.

#### Returns

(Array): Returns the new array of filtered values.

#### Example

```var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];

_.differenceWith(_.isEqual, objects, [{ 'x': 1, 'y': 2 }]);
// => [{ 'x': 2, 'y': 1 }]```

### `_.drop(n, array)`

Creates a slice of `array` with `n` elements dropped from the beginning.

0.5.0

#### Arguments

1. `n` (number): The number of elements to drop.
2. `array` (Array): The array to query.

#### Returns

(Array): Returns the slice of `array`.

#### Example

```_.drop(1, [1, 2, 3]);
// => [2, 3]

_.drop(2, [1, 2, 3]);
// => [3]

_.drop(5, [1, 2, 3]);
// => []

_.drop(0, [1, 2, 3]);
// => [1, 2, 3]```

### `_.dropRight(n, array)`

Creates a slice of `array` with `n` elements dropped from the end.

3.0.0

#### Arguments

1. `n` (number): The number of elements to drop.
2. `array` (Array): The array to query.

#### Returns

(Array): Returns the slice of `array`.

#### Example

```_.dropRight(1, [1, 2, 3]);
// => [1, 2]

_.dropRight(2, [1, 2, 3]);
// => [1]

_.dropRight(5, [1, 2, 3]);
// => []

_.dropRight(0, [1, 2, 3]);
// => [1, 2, 3]```

### `_.dropRightWhile(predicate, array)`

Creates a slice of `array` excluding elements dropped from the end. Elements are dropped until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).

3.0.0

#### Arguments

1. `predicate` (Function): The function invoked per iteration.
2. `array` (Array): The array to query.

#### Returns

(Array): Returns the slice of `array`.

#### Example

```var users = [
{ 'user': 'barney',  'active': true },
{ 'user': 'fred',    'active': false },
{ 'user': 'pebbles', 'active': false }
];

_.dropRightWhile(function(o) { return !o.active; }, users);
// => objects for ['barney']

// The `_.matches` iteratee shorthand.
_.dropRightWhile({ 'user': 'pebbles', 'active': false }, users);
// => objects for ['barney', 'fred']

// The `_.matchesProperty` iteratee shorthand.
_.dropRightWhile(['active', false], users);
// => objects for ['barney']

// The `_.property` iteratee shorthand.
_.dropRightWhile('active', users);
// => objects for ['barney', 'fred', 'pebbles']```

### `_.dropWhile(predicate, array)`

Creates a slice of `array` excluding elements dropped from the beginning. Elements are dropped until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).

3.0.0

#### Arguments

1. `predicate` (Function): The function invoked per iteration.
2. `array` (Array): The array to query.

#### Returns

(Array): Returns the slice of `array`.

#### Example

```var users = [
{ 'user': 'barney',  'active': false },
{ 'user': 'fred',    'active': false },
{ 'user': 'pebbles', 'active': true }
];

_.dropWhile(function(o) { return !o.active; }, users);
// => objects for ['pebbles']

// The `_.matches` iteratee shorthand.
_.dropWhile({ 'user': 'barney', 'active': false }, users);
// => objects for ['fred', 'pebbles']

// The `_.matchesProperty` iteratee shorthand.
_.dropWhile(['active', false], users);
// => objects for ['pebbles']

// The `_.property` iteratee shorthand.
_.dropWhile('active', users);
// => objects for ['barney', 'fred', 'pebbles']```

### `_.fill(start, end, value, array)`

Fills elements of `array` with `value` from `start` up to, but not including, `end`.

3.2.0

#### Arguments

1. `start` (number): The start position.
2. `end` (number): The end position.
3. `value` (*): The value to fill `array` with.
4. `array` (Array): The array to fill.

#### Returns

(Array): Returns `array`.

#### Example

```var array = [1, 2, 3];

_.fill(0, array.length, 'a', array);
// => ['a', 'a', 'a']

_.fill(0, Array(3).length, 2, Array(3));
// => [2, 2, 2]

_.fill(1, 3, '*', [4, 6, 8, 10]);
// => [4, '*', '*', 10]```

### `_.findIndex(predicate, array)`

This method is like `_.find` except that it returns the index of the first element `predicate` returns truthy for instead of the element itself.

1.1.0

#### Arguments

1. `predicate` (Function): The function invoked per iteration.
2. `array` (Array): The array to inspect.

#### Returns

(number): Returns the index of the found element, else `-1`.

#### Example

```var users = [
{ 'user': 'barney',  'active': false },
{ 'user': 'fred',    'active': false },
{ 'user': 'pebbles', 'active': true }
];

_.findIndex(function(o) { return o.user == 'barney'; }, users);
// => 0

// The `_.matches` iteratee shorthand.
_.findIndex({ 'user': 'fred', 'active': false }, users);
// => 1

// The `_.matchesProperty` iteratee shorthand.
_.findIndex(['active', false], users);
// => 0

// The `_.property` iteratee shorthand.
_.findIndex('active', users);
// => 2```

### `_.findLastIndex(predicate, array)`

This method is like `_.findIndex` except that it iterates over elements of `collection` from right to left.

2.0.0

#### Arguments

1. `predicate` (Function): The function invoked per iteration.
2. `array` (Array): The array to inspect.

#### Returns

(number): Returns the index of the found element, else `-1`.

#### Example

```var users = [
{ 'user': 'barney',  'active': true },
{ 'user': 'fred',    'active': false },
{ 'user': 'pebbles', 'active': false }
];

_.findLastIndex(function(o) { return o.user == 'pebbles'; }, users);
// => 2

// The `_.matches` iteratee shorthand.
_.findLastIndex({ 'user': 'barney', 'active': true }, users);
// => 0

// The `_.matchesProperty` iteratee shorthand.
_.findLastIndex(['active', false], users);
// => 2

// The `_.property` iteratee shorthand.
_.findLastIndex('active', users);
// => 0```

### `_.flatten(array)`

Flattens `array` a single level deep.

0.1.0

#### Arguments

1. `array` (Array): The array to flatten.

#### Returns

(Array): Returns the new flattened array.

#### Example

```_.flatten([1, [2, [3, [4]], 5]]);
// => [1, 2, [3, [4]], 5]```

### `_.flattenDeep(array)`

Recursively flattens `array`.

3.0.0

#### Arguments

1. `array` (Array): The array to flatten.

#### Returns

(Array): Returns the new flattened array.

#### Example

```_.flattenDeep([1, [2, [3, [4]], 5]]);
// => [1, 2, 3, 4, 5]```

### `_.flattenDepth(depth, array)`

Recursively flatten `array` up to `depth` times.

4.4.0

#### Arguments

1. `depth` (number): The maximum recursion depth.
2. `array` (Array): The array to flatten.

#### Returns

(Array): Returns the new flattened array.

#### Example

```var array = [1, [2, [3, [4]], 5]];

_.flattenDepth(1, array);
// => [1, 2, [3, [4]], 5]

_.flattenDepth(2, array);
// => [1, 2, 3, [4], 5]```

### `_.fromPairs(pairs)`

The inverse of `_.toPairs`; this method returns an object composed from key-value `pairs`.

4.0.0

#### Arguments

1. `pairs` (Array): The key-value pairs.

#### Returns

(Object): Returns the new object.

#### Example

```_.fromPairs([['a', 1], ['b', 2]]);
// => { 'a': 1, 'b': 2 }```

### `_.head(array)`

Gets the first element of `array`.

0.1.0

_.first

#### Arguments

1. `array` (Array): The array to query.

#### Returns

(*): Returns the first element of `array`.

#### Example

```_.head([1, 2, 3]);
// => 1

// => undefined```

### `_.indexOf(value, array)`

Gets the index at which the first occurrence of `value` is found in `array` using `SameValueZero` for equality comparisons. If `fromIndex` is negative, it's used as the offset from the end of `array`.

0.1.0

#### Arguments

1. `value` (*): The value to search for.
2. `array` (Array): The array to inspect.

#### Returns

(number): Returns the index of the matched value, else `-1`.

#### Example

```_.indexOf(2, [1, 2, 1, 2]);
// => 1

// Search from the `fromIndex`.
_.indexOf([2, 2], [1, 2, 1, 2]);
// => 3```

### `_.initial(array)`

Gets all but the last element of `array`.

0.1.0

#### Arguments

1. `array` (Array): The array to query.

#### Returns

(Array): Returns the slice of `array`.

#### Example

```_.initial([1, 2, 3]);
// => [1, 2]```

### `_.intersection(arrays, arrays)`

Creates an array of unique values that are included in all given arrays using `SameValueZero` for equality comparisons. The order and references of result values are determined by the first array.

0.1.0

#### Arguments

1. `arrays` (Array): The arrays to inspect.
2. `arrays` (Array): The arrays to inspect.

#### Returns

(Array): Returns the new array of intersecting values.

#### Example

```_.intersection([2, 3], [2, 1]);
// => [2]```

### `_.intersectionBy(iteratee, arrays, arrays)`

This method is like `_.intersection` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which they're compared. The order and references of result values are determined by the first array. The iteratee is invoked with one argument:
(value).

4.0.0

#### Arguments

1. `iteratee` (Function): The iteratee invoked per element.
2. `arrays` (Array): The arrays to inspect.
3. `arrays` (Array): The arrays to inspect.

#### Returns

(Array): Returns the new array of intersecting values.

#### Example

```_.intersectionBy(Math.floor, [2.1, 1.2], [2.3, 3.4]);
// => [2.1]

// The `_.property` iteratee shorthand.
_.intersectionBy('x', [{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }]);
// => [{ 'x': 1 }]```

### `_.intersectionWith(comparator, arrays, arrays)`

This method is like `_.intersection` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order and references of result values are determined by the first array. The comparator is invoked with two arguments: (arrVal, othVal).

4.0.0

#### Arguments

1. `comparator` (Function): The comparator invoked per element.
2. `arrays` (Array): The arrays to inspect.
3. `arrays` (Array): The arrays to inspect.

#### Returns

(Array): Returns the new array of intersecting values.

#### Example

```var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.intersectionWith(_.isEqual, objects, others);
// => [{ 'x': 1, 'y': 2 }]```

### `_.join(separator, array)`

Converts all elements in `array` into a string separated by `separator`.

4.0.0

#### Arguments

1. `separator` (string): The element separator.
2. `array` (Array): The array to convert.

#### Returns

(string): Returns the joined string.

#### Example

```_.join('~', ['a', 'b', 'c']);
// => 'a~b~c'```

### `_.last(array)`

Gets the last element of `array`.

0.1.0

#### Arguments

1. `array` (Array): The array to query.

#### Returns

(*): Returns the last element of `array`.

#### Example

```_.last([1, 2, 3]);
// => 3```

### `_.lastIndexOf(value, array)`

This method is like `_.indexOf` except that it iterates over elements of `array` from right to left.

0.1.0

#### Arguments

1. `value` (*): The value to search for.
2. `array` (Array): The array to inspect.

#### Returns

(number): Returns the index of the matched value, else `-1`.

#### Example

```_.lastIndexOf(2, [1, 2, 1, 2]);
// => 3

// Search from the `fromIndex`.
_.lastIndexOf([2, 2], [1, 2, 1, 2]);
// => 1```

### `_.nth(n, array)`

Gets the element at index `n` of `array`. If `n` is negative, the nth element from the end is returned.

4.11.0

#### Arguments

1. `n` (number): The index of the element to return.
2. `array` (Array): The array to query.

#### Returns

(*): Returns the nth element of `array`.

#### Example

```var array = ['a', 'b', 'c', 'd'];

_.nth(1, array);
// => 'b'

_.nth(-2, array);
// => 'c';```

### `_.pull(values, array)`

Removes all given values from `array` using `SameValueZero` for equality comparisons.

2.0.0

#### Arguments

1. `values` (*|*[]): The values to remove.
2. `array` (Array): The array to modify.

#### Returns

(Array): Returns `array`.

#### Example

```var array = ['a', 'b', 'c', 'a', 'b', 'c'];

_.pull(['a', 'c'], array);
// => ['b', 'b']```

### `_.pullAll(values, array)`

This method is like `_.pull` except that it accepts an array of values to remove.

4.0.0

#### Arguments

1. `values` (Array): The values to remove.
2. `array` (Array): The array to modify.

#### Returns

(Array): Returns `array`.

#### Example

```var array = ['a', 'b', 'c', 'a', 'b', 'c'];

_.pullAll(['a', 'c'], array);
// => ['b', 'b']```

### `_.pullAllBy(iteratee, values, array)`

This method is like `_.pullAll` except that it accepts `iteratee` which is invoked for each element of `array` and `values` to generate the criterion by which they're compared. The iteratee is invoked with one argument: (value).

4.0.0

#### Arguments

1. `iteratee` (Function): The iteratee invoked per element.
2. `values` (Array): The values to remove.
3. `array` (Array): The array to modify.

#### Returns

(Array): Returns `array`.

#### Example

```var array = [{ 'x': 1 }, { 'x': 2 }, { 'x': 3 }, { 'x': 1 }];

_.pullAllBy('x', [{ 'x': 1 }, { 'x': 3 }], array);
// => [{ 'x': 2 }]```

### `_.pullAllWith(comparator, values, array)`

This method is like `_.pullAll` except that it accepts `comparator` which is invoked to compare elements of `array` to `values`. The comparator is invoked with two arguments: (arrVal, othVal).

4.6.0

#### Arguments

1. `comparator` (Function): The comparator invoked per element.
2. `values` (Array): The values to remove.
3. `array` (Array): The array to modify.

#### Returns

(Array): Returns `array`.

#### Example

```var array = [{ 'x': 1, 'y': 2 }, { 'x': 3, 'y': 4 }, { 'x': 5, 'y': 6 }];

_.pullAllWith(_.isEqual, [{ 'x': 3, 'y': 4 }], array);
// => [{ 'x': 1, 'y': 2 }, { 'x': 5, 'y': 6 }]```

### `_.pullAt(indexes, array)`

Removes elements from `array` corresponding to `indexes` and returns an array of removed elements.

3.0.0

#### Arguments

1. `indexes` (number|number[]): The indexes of elements to remove.
2. `array` (Array): The array to modify.

#### Returns

(Array): Returns the new array of removed elements.

#### Example

```var array = ['a', 'b', 'c', 'd'];
var pulled = _.pullAt([1, 3], array);

// => ['a', 'c']

// => ['b', 'd']```

### `_.remove(predicate, array)`

Removes all elements from `array` that `predicate` returns truthy for and returns an array of the removed elements. The predicate is invoked with three arguments: (value, index, array).

2.0.0

#### Arguments

1. `predicate` (Function): The function invoked per iteration.
2. `array` (Array): The array to modify.

#### Returns

(Array): Returns the new array of removed elements.

#### Example

```var array = [1, 2, 3, 4];
var evens = _.remove(function(n) {
return n % 2 == 0;
}, array);

// => [1, 3]

// => [2, 4]```

### `_.reverse(array)`

Reverses `array` so that the first element becomes the last, the second element becomes the second to last, and so on.

4.0.0

#### Arguments

1. `array` (Array): The array to modify.

#### Returns

(Array): Returns `array`.

#### Example

```var array = [1, 2, 3];

_.reverse(array);
// => [3, 2, 1]

// => [3, 2, 1]```

### `_.slice(start, end, array)`

Creates a slice of `array` from `start` up to, but not including, `end`.

Note: This method is used instead of `Array#slice` to ensure dense arrays are returned.

3.0.0

#### Arguments

1. `start` (number): The start position.
2. `end` (number): The end position.
3. `array` (Array): The array to slice.

#### Returns

(Array): Returns the slice of `array`.

### `_.sortedIndex(value, array)`

Uses a binary search to determine the lowest index at which `value` should be inserted into `array` in order to maintain its sort order.

0.1.0

#### Arguments

1. `value` (*): The value to evaluate.
2. `array` (Array): The sorted array to inspect.

#### Returns

(number): Returns the index at which `value` should be inserted into `array`.

#### Example

```_.sortedIndex(40, [30, 50]);
// => 1```

### `_.sortedIndexBy(iteratee, value, array)`

This method is like `_.sortedIndex` except that it accepts `iteratee` which is invoked for `value` and each element of `array` to compute their sort ranking. The iteratee is invoked with one argument: (value).

4.0.0

#### Arguments

1. `iteratee` (Function): The iteratee invoked per element.
2. `value` (*): The value to evaluate.
3. `array` (Array): The sorted array to inspect.

#### Returns

(number): Returns the index at which `value` should be inserted into `array`.

#### Example

```var objects = [{ 'x': 4 }, { 'x': 5 }];

_.sortedIndexBy(function(o) { return o.x; }, { 'x': 4 }, objects);
// => 0

// The `_.property` iteratee shorthand.
_.sortedIndexBy('x', { 'x': 4 }, objects);
// => 0```

### `_.sortedIndexOf(value, array)`

This method is like `_.indexOf` except that it performs a binary search on a sorted `array`.

4.0.0

#### Arguments

1. `value` (*): The value to search for.
2. `array` (Array): The array to inspect.

#### Returns

(number): Returns the index of the matched value, else `-1`.

#### Example

```_.sortedIndexOf(5, [4, 5, 5, 5, 6]);
// => 1```

### `_.sortedLastIndex(value, array)`

This method is like `_.sortedIndex` except that it returns the highest index at which `value` should be inserted into `array` in order to maintain its sort order.

3.0.0

#### Arguments

1. `value` (*): The value to evaluate.
2. `array` (Array): The sorted array to inspect.

#### Returns

(number): Returns the index at which `value` should be inserted into `array`.

#### Example

```_.sortedLastIndex(5, [4, 5, 5, 5, 6]);
// => 4```

### `_.sortedLastIndexBy(iteratee, value, array)`

This method is like `_.sortedLastIndex` except that it accepts `iteratee` which is invoked for `value` and each element of `array` to compute their sort ranking. The iteratee is invoked with one argument: (value).

4.0.0

#### Arguments

1. `iteratee` (Function): The iteratee invoked per element.
2. `value` (*): The value to evaluate.
3. `array` (Array): The sorted array to inspect.

#### Returns

(number): Returns the index at which `value` should be inserted into `array`.

#### Example

```var objects = [{ 'x': 4 }, { 'x': 5 }];

_.sortedLastIndexBy(function(o) { return o.x; }, { 'x': 4 }, objects);
// => 1

// The `_.property` iteratee shorthand.
_.sortedLastIndexBy('x', { 'x': 4 }, objects);
// => 1```

### `_.sortedLastIndexOf(value, array)`

This method is like `_.lastIndexOf` except that it performs a binary search on a sorted `array`.

4.0.0

#### Arguments

1. `value` (*): The value to search for.
2. `array` (Array): The array to inspect.

#### Returns

(number): Returns the index of the matched value, else `-1`.

#### Example

```_.sortedLastIndexOf(5, [4, 5, 5, 5, 6]);
// => 3```

### `_.sortedUniq(array)`

This method is like `_.uniq` except that it's designed and optimized for sorted arrays.

4.0.0

#### Arguments

1. `array` (Array): The array to inspect.

#### Returns

(Array): Returns the new duplicate free array.

#### Example

```_.sortedUniq([1, 1, 2]);
// => [1, 2]```

### `_.sortedUniqBy(iteratee, array)`

This method is like `_.uniqBy` except that it's designed and optimized for sorted arrays.

4.0.0

#### Arguments

1. `iteratee` (Function): The iteratee invoked per element.
2. `array` (Array): The array to inspect.

#### Returns

(Array): Returns the new duplicate free array.

#### Example

```_.sortedUniqBy(Math.floor, [1.1, 1.2, 2.3, 2.4]);
// => [1.1, 2.3]```

### `_.tail(array)`

Gets all but the first element of `array`.

4.0.0

#### Arguments

1. `array` (Array): The array to query.

#### Returns

(Array): Returns the slice of `array`.

#### Example

```_.tail([1, 2, 3]);
// => [2, 3]```

### `_.take(n, array)`

Creates a slice of `array` with `n` elements taken from the beginning.

0.1.0

#### Arguments

1. `n` (number): The number of elements to take.
2. `array` (Array): The array to query.

#### Returns

(Array): Returns the slice of `array`.

#### Example

```_.take(1, [1, 2, 3]);
// => [1]

_.take(2, [1, 2, 3]);
// => [1, 2]

_.take(5, [1, 2, 3]);
// => [1, 2, 3]

_.take(0, [1, 2, 3]);
// => []```

### `_.takeRight(n, array)`

Creates a slice of `array` with `n` elements taken from the end.

3.0.0

#### Arguments

1. `n` (number): The number of elements to take.
2. `array` (Array): The array to query.

#### Returns

(Array): Returns the slice of `array`.

#### Example

```_.takeRight(1, [1, 2, 3]);
// => [3]

_.takeRight(2, [1, 2, 3]);
// => [2, 3]

_.takeRight(5, [1, 2, 3]);
// => [1, 2, 3]

_.takeRight(0, [1, 2, 3]);
// => []```

### `_.takeRightWhile(predicate, array)`

Creates a slice of `array` with elements taken from the end. Elements are taken until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).

3.0.0

#### Arguments

1. `predicate` (Function): The function invoked per iteration.
2. `array` (Array): The array to query.

#### Returns

(Array): Returns the slice of `array`.

#### Example

```var users = [
{ 'user': 'barney',  'active': true },
{ 'user': 'fred',    'active': false },
{ 'user': 'pebbles', 'active': false }
];

_.takeRightWhile(function(o) { return !o.active; }, users);
// => objects for ['fred', 'pebbles']

// The `_.matches` iteratee shorthand.
_.takeRightWhile({ 'user': 'pebbles', 'active': false }, users);
// => objects for ['pebbles']

// The `_.matchesProperty` iteratee shorthand.
_.takeRightWhile(['active', false], users);
// => objects for ['fred', 'pebbles']

// The `_.property` iteratee shorthand.
_.takeRightWhile('active', users);
// => []```

### `_.takeWhile(predicate, array)`

Creates a slice of `array` with elements taken from the beginning. Elements are taken until `predicate` returns falsey. The predicate is invoked with three arguments: (value, index, array).

3.0.0

#### Arguments

1. `predicate` (Function): The function invoked per iteration.
2. `array` (Array): The array to query.

#### Returns

(Array): Returns the slice of `array`.

#### Example

```var users = [
{ 'user': 'barney',  'active': false },
{ 'user': 'fred',    'active': false },
{ 'user': 'pebbles', 'active': true }
];

_.takeWhile(function(o) { return !o.active; }, users);
// => objects for ['barney', 'fred']

// The `_.matches` iteratee shorthand.
_.takeWhile({ 'user': 'barney', 'active': false }, users);
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.takeWhile(['active', false], users);
// => objects for ['barney', 'fred']

// The `_.property` iteratee shorthand.
_.takeWhile('active', users);
// => []```

### `_.union(arrays, arrays)`

Creates an array of unique values, in order, from all given arrays using `SameValueZero` for equality comparisons.

0.1.0

#### Arguments

1. `arrays` (Array): The arrays to inspect.
2. `arrays` (Array): The arrays to inspect.

#### Returns

(Array): Returns the new array of combined values.

#### Example

```_.union([1, 2], [2]);
// => [2, 1]```

### `_.unionBy(iteratee, arrays, arrays)`

This method is like `_.union` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which uniqueness is computed. Result values are chosen from the first array in which the value occurs. The iteratee is invoked with one argument:
(value).

4.0.0

#### Arguments

1. `iteratee` (Function): The iteratee invoked per element.
2. `arrays` (Array): The arrays to inspect.
3. `arrays` (Array): The arrays to inspect.

#### Returns

(Array): Returns the new array of combined values.

#### Example

```_.unionBy(Math.floor, [2.1], [1.2, 2.3]);
// => [2.1, 1.2]

// The `_.property` iteratee shorthand.
_.unionBy('x', [{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }]);
// => [{ 'x': 1 }, { 'x': 2 }]```

### `_.unionWith(comparator, arrays, arrays)`

This method is like `_.union` except that it accepts `comparator` which is invoked to compare elements of `arrays`. Result values are chosen from the first array in which the value occurs. The comparator is invoked with two arguments: (arrVal, othVal).

4.0.0

#### Arguments

1. `comparator` (Function): The comparator invoked per element.
2. `arrays` (Array): The arrays to inspect.
3. `arrays` (Array): The arrays to inspect.

#### Returns

(Array): Returns the new array of combined values.

#### Example

```var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.unionWith(_.isEqual, objects, others);
// => [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }, { 'x': 1, 'y': 1 }]```

### `_.uniq(array)`

Creates a duplicate-free version of an array, using `SameValueZero` for equality comparisons, in which only the first occurrence of each element is kept. The order of result values is determined by the order they occur in the array.

0.1.0

#### Arguments

1. `array` (Array): The array to inspect.

#### Returns

(Array): Returns the new duplicate free array.

#### Example

```_.uniq([2, 1, 2]);
// => [2, 1]```

### `_.uniqBy(iteratee, array)`

This method is like `_.uniq` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which uniqueness is computed. The order of result values is determined by the order they occur in the array. The iteratee is invoked with one argument:
(value).

4.0.0

#### Arguments

1. `iteratee` (Function): The iteratee invoked per element.
2. `array` (Array): The array to inspect.

#### Returns

(Array): Returns the new duplicate free array.

#### Example

```_.uniqBy(Math.floor, [2.1, 1.2, 2.3]);
// => [2.1, 1.2]

// The `_.property` iteratee shorthand.
_.uniqBy('x', [{ 'x': 1 }, { 'x': 2 }, { 'x': 1 }]);
// => [{ 'x': 1 }, { 'x': 2 }]```

### `_.uniqWith(comparator, array)`

This method is like `_.uniq` except that it accepts `comparator` which is invoked to compare elements of `array`. The order of result values is determined by the order they occur in the array.The comparator is invoked with two arguments: (arrVal, othVal).

4.0.0

#### Arguments

1. `comparator` (Function): The comparator invoked per element.
2. `array` (Array): The array to inspect.

#### Returns

(Array): Returns the new duplicate free array.

#### Example

```var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.uniqWith(_.isEqual, objects);
// => [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }]```

### `_.unzip(array)`

This method is like `_.zip` except that it accepts an array of grouped elements and creates an array regrouping the elements to their pre-zip configuration.

1.2.0

#### Arguments

1. `array` (Array): The array of grouped elements to process.

#### Returns

(Array): Returns the new array of regrouped elements.

#### Example

```var zipped = _.zip(['a', 'b'], [[1, 2], [true, false]]);
// => [['a', 1, true], ['b', 2, false]]

_.unzip(zipped);
// => [['a', 'b'], [1, 2], [true, false]]```

### `_.unzipWith(iteratee, array)`

This method is like `_.unzip` except that it accepts `iteratee` to specify how regrouped values should be combined. The iteratee is invoked with the elements of each group: (...group).

3.8.0

#### Arguments

1. `iteratee` (Function): The function to combine regrouped values.
2. `array` (Array): The array of grouped elements to process.

#### Returns

(Array): Returns the new array of regrouped elements.

#### Example

```var zipped = _.zip([1, 2], [[10, 20], [100, 200]]);
// => [[1, 10, 100], [2, 20, 200]]

// => [3, 30, 300]```

### `_.without(values, array)`

Creates an array excluding all given values using `SameValueZero` for equality comparisons.

Note: Unlike `_.pull`, this method returns a new array.

0.1.0

#### Arguments

1. `values` (*|*[]): The values to exclude.
2. `array` (Array): The array to inspect.

#### Returns

(Array): Returns the new array of filtered values.

#### Example

```_.without([1, 2], [2, 1, 2, 3]);
// => [3]```

### `_.xor(arrays, arrays)`

Creates an array of unique values that is the symmetric difference of the given arrays. The order of result values is determined by the order they occur in the arrays.

2.4.0

#### Arguments

1. `arrays` (Array): The arrays to inspect.
2. `arrays` (Array): The arrays to inspect.

#### Returns

(Array): Returns the new array of filtered values.

#### Example

```_.xor([2, 3], [2, 1]);
// => [1, 3]```

### `_.xorBy(iteratee, arrays, arrays)`

This method is like `_.xor` except that it accepts `iteratee` which is invoked for each element of each `arrays` to generate the criterion by which by which they're compared. The order of result values is determined by the order they occur in the arrays. The iteratee is invoked with one argument: (value).

4.0.0

#### Arguments

1. `iteratee` (Function): The iteratee invoked per element.
2. `arrays` (Array): The arrays to inspect.
3. `arrays` (Array): The arrays to inspect.

#### Returns

(Array): Returns the new array of filtered values.

#### Example

```_.xorBy(Math.floor, [2.1, 1.2], [2.3, 3.4]);
// => [1.2, 3.4]

// The `_.property` iteratee shorthand.
_.xorBy('x', [{ 'x': 1 }], [{ 'x': 2 }, { 'x': 1 }]);
// => [{ 'x': 2 }]```

### `_.xorWith(comparator, arrays, arrays)`

This method is like `_.xor` except that it accepts `comparator` which is invoked to compare elements of `arrays`. The order of result values is determined by the order they occur in the arrays. The comparator is invoked with two arguments: (arrVal, othVal).

4.0.0

#### Arguments

1. `comparator` (Function): The comparator invoked per element.
2. `arrays` (Array): The arrays to inspect.
3. `arrays` (Array): The arrays to inspect.

#### Returns

(Array): Returns the new array of filtered values.

#### Example

```var objects = [{ 'x': 1, 'y': 2 }, { 'x': 2, 'y': 1 }];
var others = [{ 'x': 1, 'y': 1 }, { 'x': 1, 'y': 2 }];

_.xorWith(_.isEqual, objects, others);
// => [{ 'x': 2, 'y': 1 }, { 'x': 1, 'y': 1 }]```

### `_.zip(arrays, arrays)`

Creates an array of grouped elements, the first of which contains the first elements of the given arrays, the second of which contains the second elements of the given arrays, and so on.

0.1.0

#### Arguments

1. `arrays` (Array): The arrays to process.
2. `arrays` (Array): The arrays to process.

#### Returns

(Array): Returns the new array of grouped elements.

#### Example

```_.zip(['a', 'b'], [[1, 2], [true, false]]);
// => [['a', 1, true], ['b', 2, false]]```

### `_.zipObject(props, values)`

This method is like `_.fromPairs` except that it accepts two arrays, one of property identifiers and one of corresponding values.

0.4.0

#### Arguments

1. `props` (Array): The property identifiers.
2. `values` (Array): The property values.

#### Returns

(Object): Returns the new object.

#### Example

```_.zipObject(['a', 'b'], [1, 2]);
// => { 'a': 1, 'b': 2 }```

### `_.zipObjectDeep(props, values)`

This method is like `_.zipObject` except that it supports property paths.

4.1.0

#### Arguments

1. `props` (Array): The property identifiers.
2. `values` (Array): The property values.

#### Returns

(Object): Returns the new object.

#### Example

```_.zipObjectDeep(['a.b[0].c', 'a.b[1].d'], [1, 2]);
// => { 'a': { 'b': [{ 'c': 1 }, { 'd': 2 }] } }```

### `_.zipWith(iteratee, arrays, arrays)`

This method is like `_.zip` except that it accepts `iteratee` to specify how grouped values should be combined. The iteratee is invoked with the elements of each group: (...group).

3.8.0

#### Arguments

1. `iteratee` (Function): The function to combine grouped values.
2. `arrays` (Array): The arrays to process.
3. `arrays` (Array): The arrays to process.

#### Returns

(Array): Returns the new array of grouped elements.

#### Example

```_.zipWith([[100, 200], function(a, b, c) {
return a + b + c;
}], [1, 2], [10, 20]);
// => [111, 222]```

## `“Collection” Methods`

### `_.countBy(iteratee, collection)`

Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the number of times the key was returned by `iteratee`. The iteratee is invoked with one argument: (value).

0.5.0

#### Arguments

1. `iteratee` (Function): The iteratee to transform keys.
2. `collection` (Array|Object): The collection to iterate over.

#### Returns

(Object): Returns the composed aggregate object.

#### Example

```_.countBy(Math.floor, [6.1, 4.2, 6.3]);
// => { '4': 1, '6': 2 }

// The `_.property` iteratee shorthand.
_.countBy('length', ['one', 'two', 'three']);
// => { '3': 2, '5': 1 }```

### `_.every(predicate, collection)`

Checks if `predicate` returns truthy for all elements of `collection`. Iteration is stopped once `predicate` returns falsey. The predicate is invoked with three arguments: (value, index|key, collection).

Note: This method returns `true` for empty collections because everything is true of elements of empty collections.

0.1.0

#### Arguments

1. `predicate` (Function): The function invoked per iteration.
2. `collection` (Array|Object): The collection to iterate over.

#### Returns

(boolean): Returns `true` if all elements pass the predicate check, else `false`.

#### Example

```_.every(Boolean, [true, 1, null, 'yes']);
// => false

var users = [
{ 'user': 'barney', 'age': 36, 'active': false },
{ 'user': 'fred',   'age': 40, 'active': false }
];

// The `_.matches` iteratee shorthand.
_.every({ 'user': 'barney', 'active': false }, users);
// => false

// The `_.matchesProperty` iteratee shorthand.
_.every(['active', false], users);
// => true

// The `_.property` iteratee shorthand.
_.every('active', users);
// => false```

### `_.filter(predicate, collection)`

Iterates over elements of `collection`, returning an array of all elements `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).

Note: Unlike `_.remove`, this method returns a new array.

0.1.0

#### Arguments

1. `predicate` (Function): The function invoked per iteration.
2. `collection` (Array|Object): The collection to iterate over.

#### Returns

(Array): Returns the new filtered array.

#### Example

```var users = [
{ 'user': 'barney', 'age': 36, 'active': true },
{ 'user': 'fred',   'age': 40, 'active': false }
];

_.filter(function(o) { return !o.active; }, users);
// => objects for ['fred']

// The `_.matches` iteratee shorthand.
_.filter({ 'age': 36, 'active': true }, users);
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.filter(['active', false], users);
// => objects for ['fred']

// The `_.property` iteratee shorthand.
_.filter('active', users);
// => objects for ['barney']

// Combining several predicates using `_.overEvery` or `_.overSome`.
_.filter(_.overSome([{ 'age': 36 }, ['age', 40]]), users);
// => objects for ['fred', 'barney']```

### `_.find(predicate, collection)`

Iterates over elements of `collection`, returning the first element `predicate` returns truthy for. The predicate is invoked with three arguments: (value, index|key, collection).

0.1.0

#### Arguments

1. `predicate` (Function): The function invoked per iteration.
2. `collection` (Array|Object): The collection to inspect.

#### Returns

(*): Returns the matched element, else `undefined`.

#### Example

```var users = [
{ 'user': 'barney',  'age': 36, 'active': true },
{ 'user': 'fred',    'age': 40, 'active': false },
{ 'user': 'pebbles', 'age': 1,  'active': true }
];

_.find(function(o) { return o.age < 40; }, users);
// => object for 'barney'

// The `_.matches` iteratee shorthand.
_.find({ 'age': 1, 'active': true }, users);
// => object for 'pebbles'

// The `_.matchesProperty` iteratee shorthand.
_.find(['active', false], users);
// => object for 'fred'

// The `_.property` iteratee shorthand.
_.find('active', users);
// => object for 'barney'```

### `_.findLast(predicate, collection)`

This method is like `_.find` except that it iterates over elements of `collection` from right to left.

2.0.0

#### Arguments

1. `predicate` (Function): The function invoked per iteration.
2. `collection` (Array|Object): The collection to inspect.

#### Returns

(*): Returns the matched element, else `undefined`.

#### Example

```_.findLast(function(n) {
return n % 2 == 1;
}, [1, 2, 3, 4]);
// => 3```

### `_.flatMap(iteratee, collection)`

Creates a flattened array of values by running each element in `collection` thru `iteratee` and flattening the mapped results. The iteratee is invoked with three arguments: (value, index|key, collection).

4.0.0

#### Arguments

1. `iteratee` (Function): The function invoked per iteration.
2. `collection` (Array|Object): The collection to iterate over.

#### Returns

(Array): Returns the new flattened array.

#### Example

```function duplicate(n) {
return [n, n];
}

_.flatMap(duplicate, [1, 2]);
// => [1, 1, 2, 2]```

### `_.flatMapDeep(iteratee, collection)`

This method is like `_.flatMap` except that it recursively flattens the mapped results.

4.7.0

#### Arguments

1. `iteratee` (Function): The function invoked per iteration.
2. `collection` (Array|Object): The collection to iterate over.

#### Returns

(Array): Returns the new flattened array.

#### Example

```function duplicate(n) {
return [[[n, n]]];
}

_.flatMapDeep(duplicate, [1, 2]);
// => [1, 1, 2, 2]```

### `_.flatMapDepth(iteratee, depth, collection)`

This method is like `_.flatMap` except that it recursively flattens the mapped results up to `depth` times.

4.7.0

#### Arguments

1. `iteratee` (Function): The function invoked per iteration.
2. `depth` (number): The maximum recursion depth.
3. `collection` (Array|Object): The collection to iterate over.

#### Returns

(Array): Returns the new flattened array.

#### Example

```function duplicate(n) {
return [[[n, n]]];
}

_.flatMapDepth(duplicate, 2, [1, 2]);
// => [[1, 1], [2, 2]]```

### `_.forEach(iteratee, collection)`

Iterates over elements of `collection` and invokes `iteratee` for each element. The iteratee is invoked with three arguments: (value, index|key, collection). Iteratee functions may exit iteration early by explicitly returning `false`.

Note: As with other "Collections" methods, objects with a "length" property are iterated like arrays. To avoid this behavior use `_.forIn` or `_.forOwn` for object iteration.

0.1.0

_.each

#### Arguments

1. `iteratee` (Function): The function invoked per iteration.
2. `collection` (Array|Object): The collection to iterate over.

#### Returns

(*): Returns `collection`.

#### Example

```_.forEach(function(value) {
console.log(value);
}, [1, 2]);
// => Logs `1` then `2`.

_.forEach(function(value, key) {
console.log(key);
}, { 'a': 1, 'b': 2 });
// => Logs 'a' then 'b' (iteration order is not guaranteed).```

### `_.forEachRight(iteratee, collection)`

This method is like `_.forEach` except that it iterates over elements of `collection` from right to left.

2.0.0

_.eachRight

#### Arguments

1. `iteratee` (Function): The function invoked per iteration.
2. `collection` (Array|Object): The collection to iterate over.

#### Returns

(*): Returns `collection`.

#### Example

```_.forEachRight(function(value) {
console.log(value);
}, [1, 2]);
// => Logs `2` then `1`.```

### `_.groupBy(iteratee, collection)`

Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The order of grouped values is determined by the order they occur in `collection`. The corresponding value of each key is an array of elements responsible for generating the key. The iteratee is invoked with one argument: (value).

0.1.0

#### Arguments

1. `iteratee` (Function): The iteratee to transform keys.
2. `collection` (Array|Object): The collection to iterate over.

#### Returns

(Object): Returns the composed aggregate object.

#### Example

```_.groupBy(Math.floor, [6.1, 4.2, 6.3]);
// => { '4': [4.2], '6': [6.1, 6.3] }

// The `_.property` iteratee shorthand.
_.groupBy('length', ['one', 'two', 'three']);
// => { '3': ['one', 'two'], '5': ['three'] }```

### `_.includes(value, collection)`

Checks if `value` is in `collection`. If `collection` is a string, it's checked for a substring of `value`, otherwise `SameValueZero` is used for equality comparisons. If `fromIndex` is negative, it's used as the offset from the end of `collection`.

0.1.0

#### Arguments

1. `value` (*): The value to search for.
2. `collection` (Array|Object|string): The collection to inspect.

#### Returns

(boolean): Returns `true` if `value` is found, else `false`.

#### Example

```_.includes(1, [1, 2, 3]);
// => true

_.includes([1, 2], [1, 2, 3]);
// => false

_.includes(1, { 'a': 1, 'b': 2 });
// => true

_.includes('bc', 'abcd');
// => true```

### `_.invokeMap(path, collection)`

Invokes the method at `path` of each element in `collection`, returning an array of the results of each invoked method. Any additional arguments are provided to each invoked method. If `path` is a function, it's invoked for, and `this` bound to, each element in `collection`.

4.0.0

#### Arguments

1. `path` (Array|Function|string): The path of the method to invoke or the function invoked per iteration.
2. `collection` (Array|Object): The collection to iterate over.

#### Returns

(Array): Returns the array of results.

#### Example

```_.invokeMap('sort', [[5, 1, 7], [3, 2, 1]]);
// => [[1, 5, 7], [1, 2, 3]]

_.invokeMap([String.prototype.split, ''], [123, 456]);
// => [['1', '2', '3'], ['4', '5', '6']]```

### `_.keyBy(iteratee, collection)`

Creates an object composed of keys generated from the results of running each element of `collection` thru `iteratee`. The corresponding value of each key is the last element responsible for generating the key. The iteratee is invoked with one argument: (value).

4.0.0

#### Arguments

1. `iteratee` (Function): The iteratee to transform keys.
2. `collection` (Array|Object): The collection to iterate over.

#### Returns

(Object): Returns the composed aggregate object.

#### Example

```var array = [
{ 'dir': 'left', 'code': 97 },
{ 'dir': 'right', 'code': 100 }
];

_.keyBy(function(o) {
return String.fromCharCode(o.code);
}, array);
// => { 'a': { 'dir': 'left', 'code': 97 }, 'd': { 'dir': 'right', 'code': 100 } }

_.keyBy('dir', array);
// => { 'left': { 'dir': 'left', 'code': 97 }, 'right': { 'dir': 'right', 'code': 100 } }```

### `_.map(iteratee, collection)`

Creates an array of values by running each element in `collection` thru `iteratee`. The iteratee is invoked with three arguments:
(value, index|key, collection).

Many lodash methods are guarded to work as iteratees for methods like `_.every`, `_.filter`, `_.map`, `_.mapValues`, `_.reject`, and `_.some`.

The guarded methods are:
`ary`, `chunk`, `curry`, `curryRight`, `drop`, `dropRight`, `every`, `fill`, `invert`, `parseInt`, `random`, `range`, `rangeRight`, `repeat`, `sampleSize`, `slice`, `some`, `sortBy`, `split`, `take`, `takeRight`, `template`, `trim`, `trimEnd`, `trimStart`, and `words`

0.1.0

#### Arguments

1. `iteratee` (Function): The function invoked per iteration.
2. `collection` (Array|Object): The collection to iterate over.

#### Returns

(Array): Returns the new mapped array.

#### Example

```function square(n) {
return n * n;
}

_.map(square, [4, 8]);
// => [16, 64]

_.map(square, { 'a': 4, 'b': 8 });
// => [16, 64] (iteration order is not guaranteed)

var users = [
{ 'user': 'barney' },
{ 'user': 'fred' }
];

// The `_.property` iteratee shorthand.
_.map('user', users);
// => ['barney', 'fred']```

### `_.orderBy(iteratees, orders, collection)`

This method is like `_.sortBy` except that it allows specifying the sort orders of the iteratees to sort by. If `orders` is unspecified, all values are sorted in ascending order. Otherwise, specify an order of "desc" for descending or "asc" for ascending sort order of corresponding values.

4.0.0

#### Arguments

1. `iteratees` (Array[]|Function[]|Object[]|string[]): The iteratees to sort by.
2. `orders` (string[]): The sort orders of `iteratees`.
3. `collection` (Array|Object): The collection to iterate over.

#### Returns

(Array): Returns the new sorted array.

#### Example

```var users = [
{ 'user': 'fred',   'age': 48 },
{ 'user': 'barney', 'age': 34 },
{ 'user': 'fred',   'age': 40 },
{ 'user': 'barney', 'age': 36 }
];

// Sort by `user` in ascending order and by `age` in descending order.
_.orderBy(['user', 'age'], ['asc', 'desc'], users);
// => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 40]]```

### `_.partition(predicate, collection)`

Creates an array of elements split into two groups, the first of which contains elements `predicate` returns truthy for, the second of which contains elements `predicate` returns falsey for. The predicate is invoked with one argument: (value).

3.0.0

#### Arguments

1. `predicate` (Function): The function invoked per iteration.
2. `collection` (Array|Object): The collection to iterate over.

#### Returns

(Array): Returns the array of grouped elements.

#### Example

```var users = [
{ 'user': 'barney',  'age': 36, 'active': false },
{ 'user': 'fred',    'age': 40, 'active': true },
{ 'user': 'pebbles', 'age': 1,  'active': false }
];

_.partition(function(o) { return o.active; }, users);
// => objects for [['fred'], ['barney', 'pebbles']]

// The `_.matches` iteratee shorthand.
_.partition({ 'age': 1, 'active': false }, users);
// => objects for [['pebbles'], ['barney', 'fred']]

// The `_.matchesProperty` iteratee shorthand.
_.partition(['active', false], users);
// => objects for [['barney', 'pebbles'], ['fred']]

// The `_.property` iteratee shorthand.
_.partition('active', users);
// => objects for [['fred'], ['barney', 'pebbles']]```

### `_.reduce(iteratee, accumulator, collection)`

Reduces `collection` to a value which is the accumulated result of running each element in `collection` thru `iteratee`, where each successive invocation is supplied the return value of the previous. If `accumulator` is not given, the first element of `collection` is used as the initial value. The iteratee is invoked with four arguments:
(accumulator, value, index|key, collection).

Many lodash methods are guarded to work as iteratees for methods like `_.reduce`, `_.reduceRight`, and `_.transform`.

The guarded methods are:
`assign`, `defaults`, `defaultsDeep`, `includes`, `merge`, `orderBy`, and `sortBy`

0.1.0

#### Arguments

1. `iteratee` (Function): The function invoked per iteration.
2. `accumulator` (*): The initial value.
3. `collection` (Array|Object): The collection to iterate over.

#### Returns

(*): Returns the accumulated value.

#### Example

```_.reduce(function(sum, n) {
return sum + n;
}, 0, [1, 2]);
// => 3

_.reduce(function(result, value, key) {
(result[value] || (result[value] = [])).push(key);
return result;
}, {}, { 'a': 1, 'b': 2, 'c': 1 });
// => { '1': ['a', 'c'], '2': ['b'] } (iteration order is not guaranteed)```

### `_.reduceRight(iteratee, accumulator, collection)`

This method is like `_.reduce` except that it iterates over elements of `collection` from right to left.

0.1.0

#### Arguments

1. `iteratee` (Function): The function invoked per iteration.
2. `accumulator` (*): The initial value.
3. `collection` (Array|Object): The collection to iterate over.

#### Returns

(*): Returns the accumulated value.

#### Example

```var array = [[0, 1], [2, 3], [4, 5]];

_.reduceRight(function(flattened, other) {
return flattened.concat(other);
}, [], array);
// => [4, 5, 2, 3, 0, 1]```

### `_.reject(predicate, collection)`

The opposite of `_.filter`; this method returns the elements of `collection` that `predicate` does not return truthy for.

0.1.0

#### Arguments

1. `predicate` (Function): The function invoked per iteration.
2. `collection` (Array|Object): The collection to iterate over.

#### Returns

(Array): Returns the new filtered array.

#### Example

```var users = [
{ 'user': 'barney', 'age': 36, 'active': false },
{ 'user': 'fred',   'age': 40, 'active': true }
];

_.reject(function(o) { return !o.active; }, users);
// => objects for ['fred']

// The `_.matches` iteratee shorthand.
_.reject({ 'age': 40, 'active': true }, users);
// => objects for ['barney']

// The `_.matchesProperty` iteratee shorthand.
_.reject(['active', false], users);
// => objects for ['fred']

// The `_.property` iteratee shorthand.
_.reject('active', users);
// => objects for ['barney']```

### `_.sample(collection)`

Gets a random element from `collection`.

2.0.0

#### Arguments

1. `collection` (Array|Object): The collection to sample.

#### Returns

(*): Returns the random element.

#### Example

```_.sample([1, 2, 3, 4]);
// => 2```

### `_.sampleSize(n, collection)`

Gets `n` random elements at unique keys from `collection` up to the size of `collection`.

4.0.0

#### Arguments

1. `n` (number): The number of elements to sample.
2. `collection` (Array|Object): The collection to sample.

#### Returns

(Array): Returns the random elements.

#### Example

```_.sampleSize(2, [1, 2, 3]);
// => [3, 1]

_.sampleSize(4, [1, 2, 3]);
// => [2, 3, 1]```

### `_.shuffle(collection)`

Creates an array of shuffled values, using a version of the Fisher-Yates shuffle.

0.1.0

#### Arguments

1. `collection` (Array|Object): The collection to shuffle.

#### Returns

(Array): Returns the new shuffled array.

#### Example

```_.shuffle([1, 2, 3, 4]);
// => [4, 1, 3, 2]```

### `_.size(collection)`

Gets the size of `collection` by returning its length for array-like values or the number of own enumerable string keyed properties for objects.

0.1.0

#### Arguments

1. `collection` (Array|Object|string): The collection to inspect.

#### Returns

(number): Returns the collection size.

#### Example

```_.size([1, 2, 3]);
// => 3

_.size({ 'a': 1, 'b': 2 });
// => 2

_.size('pebbles');
// => 7```

### `_.some(predicate, collection)`

Checks if `predicate` returns truthy for any element of `collection`. Iteration is stopped once `predicate` returns truthy. The predicate is invoked with three arguments: (value, index|key, collection).

0.1.0

#### Arguments

1. `predicate` (Function): The function invoked per iteration.
2. `collection` (Array|Object): The collection to iterate over.

#### Returns

(boolean): Returns `true` if any element passes the predicate check, else `false`.

#### Example

```_.some(Boolean, [null, 0, 'yes', false]);
// => true

var users = [
{ 'user': 'barney', 'active': true },
{ 'user': 'fred',   'active': false }
];

// The `_.matches` iteratee shorthand.
_.some({ 'user': 'barney', 'active': false }, users);
// => false

// The `_.matchesProperty` iteratee shorthand.
_.some(['active', false], users);
// => true

// The `_.property` iteratee shorthand.
_.some('active', users);
// => true```

### `_.sortBy(iteratees, collection)`

Creates an array of elements, sorted in ascending order by the results of running each element in a collection thru each iteratee. This method performs a stable sort, that is, it preserves the original sort order of equal elements. The iteratees are invoked with one argument: (value).

0.1.0

#### Arguments

1. `iteratees` (Function|Function[]): The iteratees to sort by.
2. `collection` (Array|Object): The collection to iterate over.

#### Returns

(Array): Returns the new sorted array.

#### Example

```var users = [
{ 'user': 'fred',   'age': 48 },
{ 'user': 'barney', 'age': 36 },
{ 'user': 'fred',   'age': 30 },
{ 'user': 'barney', 'age': 34 }
];

_.sortBy([function(o) { return o.user; }], users);
// => objects for [['barney', 36], ['barney', 34], ['fred', 48], ['fred', 30]]

_.sortBy(['user', 'age'], users);
// => objects for [['barney', 34], ['barney', 36], ['fred', 30], ['fred', 48]]```

## `“Date” Methods`

### `_.now()`

Gets the timestamp of the number of milliseconds that have elapsed since the Unix epoch (1 January `1970 00`:00:00 UTC).

2.4.0

#### Returns

(number): Returns the timestamp.

#### Example

```_.defer([function(stamp) {
console.log(_.now(null) - stamp);
}, _.now()]);
// => Logs the number of milliseconds it took for the deferred invocation.```

## `“Function” Methods`

### `_.after(func, n)`

The opposite of `_.before`; this method creates a function that invokes `func` once it's called `n` or more times.

0.1.0

#### Arguments

1. `func` (Function): The function to restrict.
2. `n` (number): The number of calls before `func` is invoked.

#### Returns

(Function): Returns the new restricted function.

#### Example

```var saves = ['profile', 'settings'];

var done = _.after(function() {
console.log('done saving!');
}, saves.length);

_.forEach(function(type) {
asyncSave({ 'type': type, 'complete': done });
}, saves);
// => Logs 'done saving!' after the two async saves have completed.```

### `_.ary(n, func)`

Creates a function that invokes `func`, with up to `n` arguments, ignoring any additional arguments.

3.0.0

#### Arguments

1. `n` (number): The arity cap.
2. `func` (Function): The function to cap arguments for.

#### Returns

(Function): Returns the new capped function.

#### Example

```_.map(_.ary(parseInt, 1), ['6', '8', '10']);
// => [6, 8, 10]```

### `_.before(func, n)`

Creates a function that invokes `func`, with the `this` binding and arguments of the created function, while it's called less than `n` times. Subsequent calls to the created function return the result of the last `func` invocation.

3.0.0

#### Arguments

1. `func` (Function): The function to restrict.
2. `n` (number): The number of calls at which `func` is no longer invoked.

#### Returns

(Function): Returns the new restricted function.

#### Example

```jQuery(element).on('click', _.before(addContactToList, 5));
// => Allows adding up to 4 contacts to the list.```

### `_.bind(func, thisArg)`

Creates a function that invokes `func` with the `this` binding of `thisArg` and `partials` prepended to the arguments it receives.

The `_.bind.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments.

Note: Unlike native `Function#bind`, this method doesn't set the "length" property of bound functions.

0.1.0

#### Arguments

1. `func` (Function): The function to bind.
2. `thisArg` (*): The `this` binding of `func`.

#### Returns

(Function): Returns the new bound function.

#### Example

```function greet(greeting, punctuation) {
return greeting + ' ' + this.user + punctuation;
}

var object = { 'user': 'fred' };

var bound = _.bind(greet, [object, 'hi']);
bound('!');
// => 'hi fred!'

// Bound with placeholders.
var bound = _.bind(greet, [object, _, '!']);
bound('hi');
// => 'hi fred!'```

### `_.bindKey(object, key)`

Creates a function that invokes the method at `object[key]` with `partials` prepended to the arguments it receives.

This method differs from `_.bind` by allowing bound functions to reference methods that may be redefined or don't yet exist. See Peter Michaux's article for more details.

The `_.bindKey.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments.

0.10.0

#### Arguments

1. `object` (Object): The object to invoke the method on.
2. `key` (string): The key of the method.

#### Returns

(Function): Returns the new bound function.

#### Example

```var object = {
'user': 'fred',
'greet': function(greeting, punctuation) {
return greeting + ' ' + this.user + punctuation;
}
};

var bound = _.bindKey(object, ['greet', 'hi']);
bound('!');
// => 'hi fred!'

object.greet = function(greeting, punctuation) {
return greeting + 'ya ' + this.user + punctuation;
};

bound('!');
// => 'hiya fred!'

// Bound with placeholders.
var bound = _.bindKey(object, ['greet', _, '!']);
bound('hi');
// => 'hiya fred!'```

### `_.curry(func)`

Creates a function that accepts arguments of `func` and either invokes `func` returning its result, if at least `arity` number of arguments have been provided, or returns a function that accepts the remaining `func` arguments, and so on. The arity of `func` may be specified if `func.length` is not sufficient.

The `_.curry.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for provided arguments.

Note: This method doesn't set the "length" property of curried functions.

2.0.0

#### Arguments

1. `func` (Function): The function to curry.

#### Returns

(Function): Returns the new curried function.

#### Example

```var abc = function(a, b, c) {
return [a, b, c];
};

var curried = _.curry(abc);

curried(1)(2)(3);
// => [1, 2, 3]

curried(1, 2)(3);
// => [1, 2, 3]

curried(1, 2, 3);
// => [1, 2, 3]

// Curried with placeholders.
curried(1)(_, 3)(2);
// => [1, 2, 3]```

### `_.curryRight(func)`

This method is like `_.curry` except that arguments are applied to `func` in the manner of `_.partialRight` instead of `_.partial`.

The `_.curryRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for provided arguments.

Note: This method doesn't set the "length" property of curried functions.

3.0.0

#### Arguments

1. `func` (Function): The function to curry.

#### Returns

(Function): Returns the new curried function.

#### Example

```var abc = function(a, b, c) {
return [a, b, c];
};

var curried = _.curryRight(abc);

curried(3)(2)(1);
// => [1, 2, 3]

curried(2, 3)(1);
// => [1, 2, 3]

curried(1, 2, 3);
// => [1, 2, 3]

// Curried with placeholders.
curried(3)(1, _)(2);
// => [1, 2, 3]```

### `_.debounce(wait, func)`

Creates a debounced function that delays invoking `func` until after `wait` milliseconds have elapsed since the last time the debounced function was invoked. The debounced function comes with a `cancel` method to cancel delayed `func` invocations and a `flush` method to immediately invoke them. Provide `options` to indicate whether `func` should be invoked on the leading and/or trailing edge of the `wait` timeout. The `func` is invoked with the last arguments provided to the debounced function. Subsequent calls to the debounced function return the result of the last `func` invocation.

Note: If `leading` and `trailing` options are `true`, `func` is invoked on the trailing edge of the timeout only if the debounced function is invoked more than once during the `wait` timeout.

If `wait` is `0` and `leading` is `false`, `func` invocation is deferred until to the next tick, similar to `setTimeout` with a timeout of `0`.

See David Corbacho's article for details over the differences between `_.debounce` and `_.throttle`.

0.1.0

#### Arguments

1. `wait` (number): The number of milliseconds to delay.
2. `func` (Function): The function to debounce.

#### Returns

(Function): Returns the new debounced function.

#### Example

```// Avoid costly calculations while the window size is in flux.
jQuery(window).on('resize', _.debounce(150, calculateLayout));

// Invoke `sendMail` when clicked, debouncing subsequent calls.
jQuery(element).on('click', _.debounce([300, {
'trailing': false
}], sendMail));

// Ensure `batchLog` is invoked once after 1 second of debounced calls.
var debounced = _.debounce([250, { 'maxWait': 1000 }], batchLog);
var source = new EventSource('/stream');
jQuery(source).on('message', debounced);

// Cancel the trailing debounced invocation.
jQuery(window).on('popstate', debounced.cancel);```

### `_.defer(func)`

Defers invoking the `func` until the current call stack has cleared. Any additional arguments are provided to `func` when it's invoked.

0.1.0

#### Arguments

1. `func` (Function): The function to defer.

#### Returns

(number): Returns the timer id.

#### Example

```_.defer([function(text) {
console.log(text);
}, 'deferred']);
// => Logs 'deferred' after one millisecond.```

### `_.delay(wait, func)`

Invokes `func` after `wait` milliseconds. Any additional arguments are provided to `func` when it's invoked.

0.1.0

#### Arguments

1. `wait` (number): The number of milliseconds to delay invocation.
2. `func` (Function): The function to delay.

#### Returns

(number): Returns the timer id.

#### Example

```_.delay([1000, 'later'], function(text) {
console.log(text);
});
// => Logs 'later' after one second.```

### `_.flip(func)`

Creates a function that invokes `func` with arguments reversed.

4.0.0

#### Arguments

1. `func` (Function): The function to flip arguments for.

#### Returns

(Function): Returns the new flipped function.

#### Example

```var flipped = _.flip(function() {
return _.toArray(arguments);
});

flipped('a', 'b', 'c', 'd');
// => ['d', 'c', 'b', 'a']```

### `_.memoize(func)`

Creates a function that memoizes the result of `func`. If `resolver` is provided, it determines the cache key for storing the result based on the arguments provided to the memoized function. By default, the first argument provided to the memoized function is used as the map cache key. The `func` is invoked with the `this` binding of the memoized function.

Note: The cache is exposed as the `cache` property on the memoized function. Its creation may be customized by replacing the `_.memoize.Cache` constructor with one whose instances implement the `Map` method interface of `clear`, `delete`, `get`, `has`, and `set`.

0.1.0

#### Arguments

1. `func` (Function): The function to have its output memoized.

#### Returns

(Function): Returns the new memoized function.

#### Example

```var object = { 'a': 1, 'b': 2 };
var other = { 'c': 3, 'd': 4 };

var values = _.memoize(_.values);
values(object);
// => [1, 2]

values(other);
// => [3, 4]

object.a = 2;
values(object);
// => [1, 2]

// Modify the result cache.
values.cache.set(object, ['a', 'b']);
values(object);
// => ['a', 'b']

// Replace `_.memoize.Cache`.
_.memoize.Cache = WeakMap;```

### `_.negate(predicate)`

Creates a function that negates the result of the predicate `func`. The `func` predicate is invoked with the `this` binding and arguments of the created function.

3.0.0

#### Arguments

1. `predicate` (Function): The predicate to negate.

#### Returns

(Function): Returns the new negated function.

#### Example

```function isEven(n) {
return n % 2 == 0;
}

_.filter(_.negate(isEven), [1, 2, 3, 4, 5, 6]);
// => [1, 3, 5]```

### `_.once(func)`

Creates a function that is restricted to invoking `func` once. Repeat calls to the function return the value of the first invocation. The `func` is invoked with the `this` binding and arguments of the created function.

0.1.0

#### Arguments

1. `func` (Function): The function to restrict.

#### Returns

(Function): Returns the new restricted function.

#### Example

```var initialize = _.once(createApplication);
initialize();
initialize();
// => `createApplication` is invoked once```

### `_.overArgs(func, transforms)`

Creates a function that invokes `func` with its arguments transformed.

4.0.0

#### Arguments

1. `func` (Function): The function to wrap.
2. `transforms` (Function|Function[]): The argument transforms.

#### Returns

(Function): Returns the new function.

#### Example

```function doubled(n) {
return n * 2;
}

function square(n) {
return n * n;
}

var func = _.overArgs(function(x, y) {
return [x, y];
}, [square, doubled]);

func(9, 3);
// => [81, 6]

func(10, 5);
// => [100, 10]```

### `_.partial(func, partials)`

Creates a function that invokes `func` with `partials` prepended to the arguments it receives. This method is like `_.bind` except it does not alter the `this` binding.

The `_.partial.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments.

Note: This method doesn't set the "length" property of partially applied functions.

0.2.0

#### Arguments

1. `func` (Function): The function to partially apply arguments to.
2. `partials` (*|*[]): The arguments to be partially applied.

#### Returns

(Function): Returns the new partially applied function.

#### Example

```function greet(greeting, name) {
return greeting + ' ' + name;
}

var sayHelloTo = _.partial(greet, 'hello');
sayHelloTo('fred');
// => 'hello fred'

// Partially applied with placeholders.
var greetFred = _.partial(greet, [_, 'fred']);
greetFred('hi');
// => 'hi fred'```

### `_.partialRight(func, partials)`

This method is like `_.partial` except that partially applied arguments are appended to the arguments it receives.

The `_.partialRight.placeholder` value, which defaults to `_` in monolithic builds, may be used as a placeholder for partially applied arguments.

Note: This method doesn't set the "length" property of partially applied functions.

1.0.0

#### Arguments

1. `func` (Function): The function to partially apply arguments to.
2. `partials` (*|*[]): The arguments to be partially applied.

#### Returns

(Function): Returns the new partially applied function.

#### Example

```function greet(greeting, name) {
return greeting + ' ' + name;
}

var greetFred = _.partialRight(greet, 'fred');
greetFred('hi');
// => 'hi fred'

// Partially applied with placeholders.
var sayHelloTo = _.partialRight(greet, ['hello', _]);
sayHelloTo('fred');
// => 'hello fred'```

### `_.rearg(indexes, func)`

Creates a function that invokes `func` with arguments arranged according to the specified `indexes` where the argument value at the first index is provided as the first argument, the argument value at the second index is provided as the second argument, and so on.

3.0.0

#### Arguments

1. `indexes` (number|number[]): The arranged argument indexes.
2. `func` (Function): The function to rearrange arguments for.

#### Returns

(Function): Returns the new function.

#### Example

```var rearged = _.rearg([2, 0, 1], function(a, b, c) {
return [a, b, c];
});

rearged('b', 'c', 'a')
// => ['a', 'b', 'c']```

### `_.rest(func)`

Creates a function that invokes `func` with the `this` binding of the created function and arguments from `start` and beyond provided as an array.

Note: This method is based on the rest parameter.

4.0.0

#### Arguments

1. `func` (Function): The function to apply a rest parameter to.

#### Returns

(Function): Returns the new function.

#### Example

```var say = _.rest(function(what, names) {
return what + ' ' + _.initial(names).join(', ') +
(_.size(names) > 1 ? ', & ' : '') + _.last(names);
});

say('hello', 'fred', 'barney', 'pebbles');
// => 'hello fred, barney, & pebbles'```

### `_.spread(func)`

Creates a function that invokes `func` with the `this` binding of the create function and an array of arguments much like `Function#apply`.

Note: This method is based on the spread operator.

3.2.0

#### Arguments

1. `func` (Function): The function to spread arguments over.

#### Returns

(Function): Returns the new function.

#### Example

```var say = _.spread(function(who, what) {
return who + ' says ' + what;
});

say(['fred', 'hello']);
// => 'fred says hello'

var numbers = Promise.all([
Promise.resolve(40),
Promise.resolve(36)
]);

return x + y;
}));
// => a Promise of 76```

### `_.throttle(wait, func)`

Creates a throttled function that only invokes `func` at most once per every `wait` milliseconds. The throttled function comes with a `cancel` method to cancel delayed `func` invocations and a `flush` method to immediately invoke them. Provide `options` to indicate whether `func` should be invoked on the leading and/or trailing edge of the `wait` timeout. The `func` is invoked with the last arguments provided to the throttled function. Subsequent calls to the throttled function return the result of the last `func` invocation.

Note: If `leading` and `trailing` options are `true`, `func` is invoked on the trailing edge of the timeout only if the throttled function is invoked more than once during the `wait` timeout.

If `wait` is `0` and `leading` is `false`, `func` invocation is deferred until to the next tick, similar to `setTimeout` with a timeout of `0`.

See David Corbacho's article for details over the differences between `_.throttle` and `_.debounce`.

0.1.0

#### Arguments

1. `wait` (number): The number of milliseconds to throttle invocations to.
2. `func` (Function): The function to throttle.

#### Returns

(Function): Returns the new throttled function.

#### Example

```// Avoid excessively updating the position while scrolling.
jQuery(window).on('scroll', _.throttle(100, updatePosition));

// Invoke `renewToken` when the click event is fired, but not more than once every 5 minutes.
var throttled = _.throttle([300000, { 'trailing': false }], renewToken);
jQuery(element).on('click', throttled);

// Cancel the trailing throttled invocation.
jQuery(window).on('popstate', throttled.cancel);```

### `_.unary(func)`

Creates a function that accepts up to one argument, ignoring any additional arguments.

4.0.0

#### Arguments

1. `func` (Function): The function to cap arguments for.

#### Returns

(Function): Returns the new capped function.

#### Example

```_.map(_.unary(parseInt), ['6', '8', '10']);
// => [6, 8, 10]```

### `_.wrap(wrapper, value)`

Creates a function that provides `value` to `wrapper` as its first argument. Any additional arguments provided to the function are appended to those provided to the `wrapper`. The wrapper is invoked with the `this` binding of the created function.

0.1.0

#### Arguments

1. `wrapper` (Function): The wrapper function.
2. `value` (*): The value to wrap.

#### Returns

(Function): Returns the new function.

#### Example

```var p = _.wrap(function(func, text) {
return '<p>' + func(text) + '</p>';
}, _.escape);

p('fred, barney, & pebbles');
// => '<p>fred, barney, &amp; pebbles</p>'```

## `“Lang” Methods`

### `_.castArray(value)`

Casts `value` as an array if it's not one.

4.4.0

#### Arguments

1. `value` (*): The value to inspect.

#### Returns

(Array): Returns the cast array.

#### Example

```_.castArray(1);
// => [1]

_.castArray({ 'a': 1 });
// => [{ 'a': 1 }]

_.castArray('abc');
// => ['abc']

_.castArray(null);
// => [null]

_.castArray(undefined);
// => [undefined]

_.castArray(null);
// => []

var array = [1, 2, 3];
// => true```

### `_.clone(value)`

Creates a shallow clone of `value`.

Note: This method is loosely based on the structured clone algorithm and supports cloning arrays, array buffers, booleans, date objects, maps, numbers, `Object` objects, regexes, sets, strings, symbols, and typed arrays. The own enumerable properties of `arguments` objects are cloned as plain objects. An empty object is returned for uncloneable values such as error objects, functions, DOM nodes, and WeakMaps.

0.1.0

#### Arguments

1. `value` (*): The value to clone.

#### Returns

(*): Returns the cloned value.

#### Example

```var objects = [{ 'a': 1 }, { 'b': 2 }];

var shallow = _.clone(objects);
// => true```

### `_.cloneDeep(value)`

This method is like `_.clone` except that it recursively clones `value`.

1.0.0

#### Arguments

1. `value` (*): The value to recursively clone.

#### Returns

(*): Returns the deep cloned value.

#### Example

```var objects = [{ 'a': 1 }, { 'b': 2 }];

var deep = _.cloneDeep(objects);
// => false```

### `_.cloneDeepWith(customizer, value)`

This method is like `_.cloneWith` except that it recursively clones `value`.

4.0.0

#### Arguments

1. `customizer` (Function): The function to customize cloning.
2. `value` (*): The value to recursively clone.

#### Returns

(*): Returns the deep cloned value.

#### Example

```function customizer(value) {
if (_.isElement(value)) {
return value.cloneNode(true);
}
}

var el = _.cloneDeepWith(customizer, document.body);

// => false
// => 'BODY'
// => 20```

### `_.cloneWith(customizer, value)`

This method is like `_.clone` except that it accepts `customizer` which is invoked to produce the cloned value. If `customizer` returns `undefined`, cloning is handled by the method instead. The `customizer` is invoked with up to four arguments; (value [, index|key, object, stack]).

4.0.0

#### Arguments

1. `customizer` (Function): The function to customize cloning.
2. `value` (*): The value to clone.

#### Returns

(*): Returns the cloned value.

#### Example

```function customizer(value) {
if (_.isElement(value)) {
return value.cloneNode(false);
}
}

var el = _.cloneWith(customizer, document.body);

// => false
// => 'BODY'
// => 0```

### `_.conformsTo(source, object)`

Checks if `object` conforms to `source` by invoking the predicate properties of `source` with the corresponding property values of `object`.

Note: This method is equivalent to `_.conforms` when `source` is partially applied.

4.14.0

#### Arguments

1. `source` (Object): The object of property predicates to conform to.
2. `object` (Object): The object to inspect.

#### Returns

(boolean): Returns `true` if `object` conforms, else `false`.

#### Example

```var object = { 'a': 1, 'b': 2 };

_.conformsTo({ 'b': function(n) { return n > 1; } }, object);
// => true

_.conformsTo({ 'b': function(n) { return n > 2; } }, object);
// => false```

### `_.eq(value, other)`

Performs a `SameValueZero` comparison between two values to determine if they are equivalent.

4.0.0

#### Arguments

1. `value` (*): The value to compare.
2. `other` (*): The other value to compare.

#### Returns

(boolean): Returns `true` if the values are equivalent, else `false`.

#### Example

```var object = { 'a': 1 };
var other = { 'a': 1 };

_.eq(object, object);
// => true

_.eq(object, other);
// => false

_.eq('a', 'a');
// => true

_.eq('a', Object('a'));
// => false

_.eq(NaN, NaN);
// => true```

### `_.gt(value, other)`

Checks if `value` is greater than `other`.

3.9.0

#### Arguments

1. `value` (*): The value to compare.
2. `other` (*): The other value to compare.

#### Returns

(boolean): Returns `true` if `value` is greater than `other`, else `false`.

#### Example

```_.gt(3, 1);
// => true

_.gt(3, 3);
// => false

_.gt(1, 3);
// => false```

### `_.gte(value, other)`

Checks if `value` is greater than or equal to `other`.

3.9.0

#### Arguments

1. `value` (*): The value to compare.
2. `other` (*): The other value to compare.

#### Returns

(boolean): Returns `true` if `value` is greater than or equal to `other`, else `false`.

#### Example

```_.gte(3, 1);
// => true

_.gte(3, 3);
// => true

_.gte(1, 3);
// => false```

### `_.isArguments(value)`

Checks if `value` is likely an `arguments` object.

0.1.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is an `arguments` object, else `false`.

#### Example

```_.isArguments(function() { return arguments; }());
// => true

_.isArguments([1, 2, 3]);
// => false```

### `_.isArray(value)`

Checks if `value` is classified as an `Array` object.

0.1.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is an array, else `false`.

#### Example

```_.isArray([1, 2, 3]);
// => true

_.isArray(document.body.children);
// => false

_.isArray('abc');
// => false

_.isArray(_.noop);
// => false```

### `_.isArrayBuffer(value)`

Checks if `value` is classified as an `ArrayBuffer` object.

4.3.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is an array buffer, else `false`.

#### Example

```_.isArrayBuffer(new ArrayBuffer(2));
// => true

_.isArrayBuffer(new Array(2));
// => false```

### `_.isArrayLike(value)`

Checks if `value` is array-like. A value is considered array-like if it's not a function and has a `value.length` that's an integer greater than or equal to `0` and less than or equal to `Number.MAX_SAFE_INTEGER`.

4.0.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is array-like, else `false`.

#### Example

```_.isArrayLike([1, 2, 3]);
// => true

_.isArrayLike(document.body.children);
// => true

_.isArrayLike('abc');
// => true

_.isArrayLike(_.noop);
// => false```

### `_.isArrayLikeObject(value)`

This method is like `_.isArrayLike` except that it also checks if `value` is an object.

4.0.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is an array-like object, else `false`.

#### Example

```_.isArrayLikeObject([1, 2, 3]);
// => true

_.isArrayLikeObject(document.body.children);
// => true

_.isArrayLikeObject('abc');
// => false

_.isArrayLikeObject(_.noop);
// => false```

### `_.isBoolean(value)`

Checks if `value` is classified as a boolean primitive or object.

0.1.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is a boolean, else `false`.

#### Example

```_.isBoolean(false);
// => true

_.isBoolean(null);
// => false```

### `_.isBuffer(value)`

Checks if `value` is a buffer.

4.3.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is a buffer, else `false`.

#### Example

```_.isBuffer(new Buffer(2));
// => true

_.isBuffer(new Uint8Array(2));
// => false```

### `_.isDate(value)`

Checks if `value` is classified as a `Date` object.

0.1.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is a date object, else `false`.

#### Example

```_.isDate(new Date);
// => true

_.isDate('Mon April 23 2012');
// => false```

### `_.isElement(value)`

Checks if `value` is likely a DOM element.

0.1.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is a DOM element, else `false`.

#### Example

```_.isElement(document.body);
// => true

_.isElement('<body>');
// => false```

### `_.isEmpty(value)`

Checks if `value` is an empty object, collection, map, or set.

Objects are considered empty if they have no own enumerable string keyed properties.

Array-like values such as `arguments` objects, arrays, buffers, strings, or jQuery-like collections are considered empty if they have a `length` of `0`. Similarly, maps and sets are considered empty if they have a `size` of `0`.

0.1.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is empty, else `false`.

#### Example

```_.isEmpty(null);
// => true

_.isEmpty(true);
// => true

_.isEmpty(1);
// => true

_.isEmpty([1, 2, 3]);
// => false

_.isEmpty({ 'a': 1 });
// => false```

### `_.isEqual(value, other)`

Performs a deep comparison between two values to determine if they are equivalent.

Note: This method supports comparing arrays, array buffers, booleans, date objects, error objects, maps, numbers, `Object` objects, regexes, sets, strings, symbols, and typed arrays. `Object` objects are compared by their own, not inherited, enumerable properties. Functions and DOM nodes are compared by strict equality, i.e. `===`.

0.1.0

#### Arguments

1. `value` (*): The value to compare.
2. `other` (*): The other value to compare.

#### Returns

(boolean): Returns `true` if the values are equivalent, else `false`.

#### Example

```var object = { 'a': 1 };
var other = { 'a': 1 };

_.isEqual(object, other);
// => true

object === other;
// => false```

### `_.isEqualWith(customizer, value, other)`

This method is like `_.isEqual` except that it accepts `customizer` which is invoked to compare values. If `customizer` returns `undefined`, comparisons are handled by the method instead. The `customizer` is invoked with up to six arguments: (objValue, othValue [, index|key, object, other, stack]).

4.0.0

#### Arguments

1. `customizer` (Function): The function to customize comparisons.
2. `value` (*): The value to compare.
3. `other` (*): The other value to compare.

#### Returns

(boolean): Returns `true` if the values are equivalent, else `false`.

#### Example

```function isGreeting(value) {
return /^h(?:i|ello)\$/.test(value);
}

function customizer(objValue, othValue) {
if (isGreeting(objValue) && isGreeting(othValue)) {
return true;
}
}

var array = ['hello', 'goodbye'];
var other = ['hi', 'goodbye'];

_.isEqualWith(customizer, array, other);
// => true```

### `_.isError(value)`

Checks if `value` is an `Error`, `EvalError`, `RangeError`, `ReferenceError`, `SyntaxError`, `TypeError`, or `URIError` object.

3.0.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is an error object, else `false`.

#### Example

```_.isError(new Error);
// => true

_.isError(Error);
// => false```

### `_.isFinite(value)`

Checks if `value` is a finite primitive number.

Note: This method is based on `Number.isFinite`.

0.1.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is a finite number, else `false`.

#### Example

```_.isFinite(3);
// => true

_.isFinite(Number.MIN_VALUE);
// => true

_.isFinite(Infinity);
// => false

_.isFinite('3');
// => false```

### `_.isFunction(value)`

Checks if `value` is classified as a `Function` object.

0.1.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is a function, else `false`.

#### Example

```_.isFunction(_);
// => true

_.isFunction(/abc/);
// => false```

### `_.isInteger(value)`

Checks if `value` is an integer.

Note: This method is based on `Number.isInteger`.

4.0.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is an integer, else `false`.

#### Example

```_.isInteger(3);
// => true

_.isInteger(Number.MIN_VALUE);
// => false

_.isInteger(Infinity);
// => false

_.isInteger('3');
// => false```

### `_.isLength(value)`

Checks if `value` is a valid array-like length.

Note: This method is loosely based on `ToLength`.

4.0.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is a valid length, else `false`.

#### Example

```_.isLength(3);
// => true

_.isLength(Number.MIN_VALUE);
// => false

_.isLength(Infinity);
// => false

_.isLength('3');
// => false```

### `_.isMap(value)`

Checks if `value` is classified as a `Map` object.

4.3.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is a map, else `false`.

#### Example

```_.isMap(new Map);
// => true

_.isMap(new WeakMap);
// => false```

### `_.isMatch(source, object)`

Performs a partial deep comparison between `object` and `source` to determine if `object` contains equivalent property values.

Note: This method is equivalent to `_.matches` when `source` is partially applied.

Partial comparisons will match empty array and empty object `source` values against any array or object value, respectively. See `_.isEqual` for a list of supported value comparisons.

3.0.0

#### Arguments

1. `source` (Object): The object of property values to match.
2. `object` (Object): The object to inspect.

#### Returns

(boolean): Returns `true` if `object` is a match, else `false`.

#### Example

```var object = { 'a': 1, 'b': 2 };

_.isMatch({ 'b': 2 }, object);
// => true

_.isMatch({ 'b': 1 }, object);
// => false```

### `_.isMatchWith(customizer, source, object)`

This method is like `_.isMatch` except that it accepts `customizer` which is invoked to compare values. If `customizer` returns `undefined`, comparisons are handled by the method instead. The `customizer` is invoked with five arguments: (objValue, srcValue, index|key, object, source).

4.0.0

#### Arguments

1. `customizer` (Function): The function to customize comparisons.
2. `source` (Object): The object of property values to match.
3. `object` (Object): The object to inspect.

#### Returns

(boolean): Returns `true` if `object` is a match, else `false`.

#### Example

```function isGreeting(value) {
return /^h(?:i|ello)\$/.test(value);
}

function customizer(objValue, srcValue) {
if (isGreeting(objValue) && isGreeting(srcValue)) {
return true;
}
}

var object = { 'greeting': 'hello' };
var source = { 'greeting': 'hi' };

_.isMatchWith(customizer, source, object);
// => true```

### `_.isNaN(value)`

Checks if `value` is `NaN`.

Note: This method is based on `Number.isNaN` and is not the same as global `isNaN` which returns `true` for `undefined` and other non-number values.

0.1.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is `NaN`, else `false`.

#### Example

```_.isNaN(NaN);
// => true

_.isNaN(new Number(NaN));
// => true

isNaN(undefined);
// => true

_.isNaN(undefined);
// => false```

### `_.isNative(value)`

Checks if `value` is a pristine native function.

Note: This method can't reliably detect native functions in the presence of the core-js package because core-js circumvents this kind of detection. Despite multiple requests, the core-js maintainer has made it clear: any attempt to fix the detection will be obstructed. As a result, we're left with little choice but to throw an error. Unfortunately, this also affects packages, like babel-polyfill, which rely on core-js.

3.0.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is a native function, else `false`.

#### Example

```_.isNative(Array.prototype.push);
// => true

_.isNative(_);
// => false```

### `_.isNil(value)`

Checks if `value` is `null` or `undefined`.

4.0.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is nullish, else `false`.

#### Example

```_.isNil(null);
// => true

_.isNil(void 0);
// => true

_.isNil(NaN);
// => false```

### `_.isNull(value)`

Checks if `value` is `null`.

0.1.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is `null`, else `false`.

#### Example

```_.isNull(null);
// => true

_.isNull(void 0);
// => false```

### `_.isNumber(value)`

Checks if `value` is classified as a `Number` primitive or object.

Note: To exclude `Infinity`, `-Infinity`, and `NaN`, which are classified as numbers, use the `_.isFinite` method.

0.1.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is a number, else `false`.

#### Example

```_.isNumber(3);
// => true

_.isNumber(Number.MIN_VALUE);
// => true

_.isNumber(Infinity);
// => true

_.isNumber('3');
// => false```

### `_.isObject(value)`

Checks if `value` is the language type of `Object`. (e.g. arrays, functions, objects, regexes, `new Number(0)`, and `new String('')`)

0.1.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is an object, else `false`.

#### Example

```_.isObject({});
// => true

_.isObject([1, 2, 3]);
// => true

_.isObject(_.noop);
// => true

_.isObject(null);
// => false```

### `_.isObjectLike(value)`

Checks if `value` is object-like. A value is object-like if it's not `null` and has a `typeof` result of "object".

4.0.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is object-like, else `false`.

#### Example

```_.isObjectLike({});
// => true

_.isObjectLike([1, 2, 3]);
// => true

_.isObjectLike(_.noop);
// => false

_.isObjectLike(null);
// => false```

### `_.isPlainObject(value)`

Checks if `value` is a plain object, that is, an object created by the `Object` constructor or one with a `[[Prototype]]` of `null`.

0.8.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is a plain object, else `false`.

#### Example

```function Foo() {
this.a = 1;
}

_.isPlainObject(new Foo);
// => false

_.isPlainObject([1, 2, 3]);
// => false

_.isPlainObject({ 'x': 0, 'y': 0 });
// => true

_.isPlainObject(Object.create(null));
// => true```

### `_.isRegExp(value)`

Checks if `value` is classified as a `RegExp` object.

0.1.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is a regexp, else `false`.

#### Example

```_.isRegExp(/abc/);
// => true

_.isRegExp('/abc/');
// => false```

### `_.isSafeInteger(value)`

Checks if `value` is a safe integer. An integer is safe if it's an IEEE-754 double precision number which isn't the result of a rounded unsafe integer.

Note: This method is based on `Number.isSafeInteger`.

4.0.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is a safe integer, else `false`.

#### Example

```_.isSafeInteger(3);
// => true

_.isSafeInteger(Number.MIN_VALUE);
// => false

_.isSafeInteger(Infinity);
// => false

_.isSafeInteger('3');
// => false```

### `_.isSet(value)`

Checks if `value` is classified as a `Set` object.

4.3.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is a set, else `false`.

#### Example

```_.isSet(new Set);
// => true

_.isSet(new WeakSet);
// => false```

### `_.isString(value)`

Checks if `value` is classified as a `String` primitive or object.

0.1.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is a string, else `false`.

#### Example

```_.isString('abc');
// => true

_.isString(1);
// => false```

### `_.isSymbol(value)`

Checks if `value` is classified as a `Symbol` primitive or object.

4.0.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is a symbol, else `false`.

#### Example

```_.isSymbol(Symbol.iterator);
// => true

_.isSymbol('abc');
// => false```

### `_.isTypedArray(value)`

Checks if `value` is classified as a typed array.

3.0.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is a typed array, else `false`.

#### Example

```_.isTypedArray(new Uint8Array);
// => true

_.isTypedArray([]);
// => false```

### `_.isUndefined(value)`

Checks if `value` is `undefined`.

0.1.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is `undefined`, else `false`.

#### Example

```_.isUndefined(void 0);
// => true

_.isUndefined(null);
// => false```

### `_.isWeakMap(value)`

Checks if `value` is classified as a `WeakMap` object.

4.3.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is a weak map, else `false`.

#### Example

```_.isWeakMap(new WeakMap);
// => true

_.isWeakMap(new Map);
// => false```

### `_.isWeakSet(value)`

Checks if `value` is classified as a `WeakSet` object.

4.3.0

#### Arguments

1. `value` (*): The value to check.

#### Returns

(boolean): Returns `true` if `value` is a weak set, else `false`.

#### Example

```_.isWeakSet(new WeakSet);
// => true

_.isWeakSet(new Set);
// => false```

### `_.lt(value, other)`

Checks if `value` is less than `other`.

3.9.0

#### Arguments

1. `value` (*): The value to compare.
2. `other` (*): The other value to compare.

#### Returns

(boolean): Returns `true` if `value` is less than `other`, else `false`.

#### Example

```_.lt(1, 3);
// => true

_.lt(3, 3);
// => false

_.lt(3, 1);
// => false```

### `_.lte(value, other)`

Checks if `value` is less than or equal to `other`.

3.9.0

#### Arguments

1. `value` (*): The value to compare.
2. `other` (*): The other value to compare.

#### Returns

(boolean): Returns `true` if `value` is less than or equal to `other`, else `false`.

#### Example

```_.lte(1, 3);
// => true

_.lte(3, 3);
// => true

_.lte(3, 1);
// => false```

### `_.toArray(value)`

Converts `value` to an array.

0.1.0

#### Arguments

1. `value` (*): The value to convert.

#### Returns

(Array): Returns the converted array.

#### Example

```_.toArray({ 'a': 1, 'b': 2 });
// => [1, 2]

_.toArray('abc');
// => ['a', 'b', 'c']

_.toArray(1);
// => []

_.toArray(null);
// => []```

### `_.toFinite(value)`

Converts `value` to a finite number.

4.12.0

#### Arguments

1. `value` (*): The value to convert.

#### Returns

(number): Returns the converted number.

#### Example

```_.toFinite(3.2);
// => 3.2

_.toFinite(Number.MIN_VALUE);
// => 5e-324

_.toFinite(Infinity);
// => 1.7976931348623157e+308

_.toFinite('3.2');
// => 3.2```

### `_.toInteger(value)`

Converts `value` to an integer.

Note: This method is loosely based on `ToInteger`.

4.0.0

#### Arguments

1. `value` (*): The value to convert.

#### Returns

(number): Returns the converted integer.

#### Example

```_.toInteger(3.2);
// => 3

_.toInteger(Number.MIN_VALUE);
// => 0

_.toInteger(Infinity);
// => 1.7976931348623157e+308

_.toInteger('3.2');
// => 3```

### `_.toLength(value)`

Converts `value` to an integer suitable for use as the length of an array-like object.

Note: This method is based on `ToLength`.

4.0.0

#### Arguments

1. `value` (*): The value to convert.

#### Returns

(number): Returns the converted integer.

#### Example

```_.toLength(3.2);
// => 3

_.toLength(Number.MIN_VALUE);
// => 0

_.toLength(Infinity);
// => 4294967295

_.toLength('3.2');
// => 3```

### `_.toNumber(value)`

Converts `value` to a number.

4.0.0

#### Arguments

1. `value` (*): The value to process.

#### Returns

(number): Returns the number.

#### Example

```_.toNumber(3.2);
// => 3.2

_.toNumber(Number.MIN_VALUE);
// => 5e-324

_.toNumber(Infinity);
// => Infinity

_.toNumber('3.2');
// => 3.2```

### `_.toPlainObject(value)`

Converts `value` to a plain object flattening inherited enumerable string keyed properties of `value` to own properties of the plain object.

3.0.0

#### Arguments

1. `value` (*): The value to convert.

#### Returns

(Object): Returns the converted plain object.

#### Example

```function Foo() {
this.b = 2;
}

Foo.prototype.c = 3;

_.assign({ 'a': 1 }, new Foo);
// => { 'a': 1, 'b': 2 }

_.assign({ 'a': 1 }, _.toPlainObject(new Foo));
// => { 'a': 1, 'b': 2, 'c': 3 }```

### `_.toSafeInteger(value)`

Converts `value` to a safe integer. A safe integer can be compared and represented correctly.

4.0.0

#### Arguments

1. `value` (*): The value to convert.

#### Returns

(number): Returns the converted integer.

#### Example

```_.toSafeInteger(3.2);
// => 3

_.toSafeInteger(Number.MIN_VALUE);
// => 0

_.toSafeInteger(Infinity);
// => 9007199254740991

_.toSafeInteger('3.2');
// => 3```

### `_.toString(value)`

Converts `value` to a string. An empty string is returned for `null` and `undefined` values. The sign of `-0` is preserved.

4.0.0

#### Arguments

1. `value` (*): The value to convert.

#### Returns

(string): Returns the converted string.

#### Example

```_.toString(null);
// => ''

_.toString(-0);
// => '-0'

_.toString([1, 2, 3]);
// => '1,2,3'```

## `“Math” Methods`

### `_.add(augend, addend)`

3.4.0

#### Arguments

1. `augend` (number): The first number in an addition.
2. `addend` (number): The second number in an addition.

#### Returns

(number): Returns the total.

#### Example

```_.add(6, 4);
// => 10```

### `_.ceil(number)`

Computes `number` rounded up to `precision`.

3.10.0

#### Arguments

1. `number` (number): The number to round up.

#### Returns

(number): Returns the rounded up number.

#### Example

```_.ceil(4.006);
// => 5

_.ceil([6.004, 2]);
// => 6.01

_.ceil([6040, -2]);
// => 6100```

### `_.divide(dividend, divisor)`

Divide two numbers.

4.7.0

#### Arguments

1. `dividend` (number): The first number in a division.
2. `divisor` (number): The second number in a division.

#### Returns

(number): Returns the quotient.

#### Example

```_.divide(6, 4);
// => 1.5```

### `_.floor(number)`

Computes `number` rounded down to `precision`.

3.10.0

#### Arguments

1. `number` (number): The number to round down.

#### Returns

(number): Returns the rounded down number.

#### Example

```_.floor(4.006);
// => 4

_.floor([0.046, 2]);
// => 0.04

_.floor([4060, -2]);
// => 4000```

### `_.max(array)`

Computes the maximum value of `array`. If `array` is empty or falsey, `undefined` is returned.

0.1.0

#### Arguments

1. `array` (Array): The array to iterate over.

#### Returns

(*): Returns the maximum value.

#### Example

```_.max([4, 2, 8, 6]);
// => 8

_.max([]);
// => undefined```

### `_.maxBy(iteratee, array)`

This method is like `_.max` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which the value is ranked. The iteratee is invoked with one argument: (value).

4.0.0

#### Arguments

1. `iteratee` (Function): The iteratee invoked per element.
2. `array` (Array): The array to iterate over.

#### Returns

(*): Returns the maximum value.

#### Example

```var objects = [{ 'n': 1 }, { 'n': 2 }];

_.maxBy(function(o) { return o.n; }, objects);
// => { 'n': 2 }

// The `_.property` iteratee shorthand.
_.maxBy('n', objects);
// => { 'n': 2 }```

### `_.mean(array)`

Computes the mean of the values in `array`.

4.0.0

#### Arguments

1. `array` (Array): The array to iterate over.

#### Returns

(number): Returns the mean.

#### Example

```_.mean([4, 2, 8, 6]);
// => 5```

### `_.meanBy(iteratee, array)`

This method is like `_.mean` except that it accepts `iteratee` which is invoked for each element in `array` to generate the value to be averaged. The iteratee is invoked with one argument: (value).

4.7.0

#### Arguments

1. `iteratee` (Function): The iteratee invoked per element.
2. `array` (Array): The array to iterate over.

#### Returns

(number): Returns the mean.

#### Example

```var objects = [{ 'n': 4 }, { 'n': 2 }, { 'n': 8 }, { 'n': 6 }];

_.meanBy(function(o) { return o.n; }, objects);
// => 5

// The `_.property` iteratee shorthand.
_.meanBy('n', objects);
// => 5```

### `_.min(array)`

Computes the minimum value of `array`. If `array` is empty or falsey, `undefined` is returned.

0.1.0

#### Arguments

1. `array` (Array): The array to iterate over.

#### Returns

(*): Returns the minimum value.

#### Example

```_.min([4, 2, 8, 6]);
// => 2

_.min([]);
// => undefined```

### `_.minBy(iteratee, array)`

This method is like `_.min` except that it accepts `iteratee` which is invoked for each element in `array` to generate the criterion by which the value is ranked. The iteratee is invoked with one argument: (value).

4.0.0

#### Arguments

1. `iteratee` (Function): The iteratee invoked per element.
2. `array` (Array): The array to iterate over.

#### Returns

(*): Returns the minimum value.

#### Example

```var objects = [{ 'n': 1 }, { 'n': 2 }];

_.minBy(function(o) { return o.n; }, objects);
// => { 'n': 1 }

// The `_.property` iteratee shorthand.
_.minBy('n', objects);
// => { 'n': 1 }```

### `_.multiply(multiplier, multiplicand)`

Multiply two numbers.

4.7.0

#### Arguments

1. `multiplier` (number): The first number in a multiplication.
2. `multiplicand` (number): The second number in a multiplication.

#### Returns

(number): Returns the product.

#### Example

```_.multiply(6, 4);
// => 24```

### `_.round(number)`

Computes `number` rounded to `precision`.

3.10.0