A collection of JavaScript Array prototype updates.

array.coffee

# Info: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/defineProperty
# Info: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array
# Source: https://gist.github.com/jgphilpott/a1367ca419ac2807ed4340d69356b7f1

Object.defineProperty Array.prototype, "first",

    value: ->

        this.at 0

    configurable: false,
    enumerable: false,
    writable: false

Object.defineProperty Array.prototype, "last",

    value: ->

        this.at -1

    configurable: false,
    enumerable: false,
    writable: false

Object.defineProperty Array.prototype, "clear",

    value: ->

        this.length = 0

    configurable: false,
    enumerable: false,
    writable: false

Object.defineProperty Array.prototype, "empty",

    value: ->

        this.length is 0

    configurable: false,
    enumerable: false,
    writable: false

Object.defineProperty Array.prototype, "boolean",

    value: ->

        Boolean this.length

    configurable: false,
    enumerable: false,
    writable: false

Object.defineProperty Array.prototype, "number",

    value: ->

        Number this

    configurable: false,
    enumerable: false,
    writable: false

Object.defineProperty Array.prototype, "string",

    value: ->

        String this

    configurable: false,
    enumerable: false,
    writable: false

Object.defineProperty Array.prototype, "array",

    value: ->

        Array this

    configurable: false,
    enumerable: false,
    writable: false

Object.defineProperty Array.prototype, "object",

    value: ->

        Object this

    configurable: false,
    enumerable: false,
    writable: false

Object.defineProperty Array.prototype, "sum",

    value: ->

        numeric = this.numeric()

        if not numeric.empty()

            return numeric.reduce((a, b) -> a + b)

        else

            return 0

    configurable: false,
    enumerable: false,
    writable: false

Object.defineProperty Array.prototype, "difference",

    value: ->

        numeric = this.numeric()

        if not numeric.empty()

            return numeric.reduce((a, b) -> a - b)

        else

            return 0

    configurable: false,
    enumerable: false,
    writable: false

Object.defineProperty Array.prototype, "product",

    value: ->

        numeric = this.numeric()

        if not numeric.empty()

            return numeric.reduce((a, b) -> a * b)

        else

            return 0

    configurable: false,
    enumerable: false,
    writable: false

Object.defineProperty Array.prototype, "quotient",

    value: ->

        numeric = this.numeric()

        if not numeric.empty()

            return numeric.reduce((a, b) -> a / b)

        else

            return 0

    configurable: false,
    enumerable: false,
    writable: false

Object.defineProperty Array.prototype, "min",

    value: (numeric = true) ->

        if numeric

            return Math.min.apply null, this.numeric()

        else

            return this.sort().first()

    configurable: false,
    enumerable: false,
    writable: false

Object.defineProperty Array.prototype, "max",

    value: (numeric = true) ->

        if numeric

            return Math.max.apply null, this.numeric()

        else

            return this.sort().last()

    configurable: false,
    enumerable: false,
    writable: false

Object.defineProperty Array.prototype, "absMin",

    value: (numeric = true) ->

        if numeric

            return Math.min.apply null, this.numeric().map Math.abs

        else

            return this.sort().first()

    configurable: false,
    enumerable: false,
    writable: false

Object.defineProperty Array.prototype, "absMax",

    value: (numeric = true) ->

        if numeric

            return Math.max.apply null, this.numeric().map Math.abs

        else

            return this.sort().last()

    configurable: false,
    enumerable: false,
    writable: false

Object.defineProperty Array.prototype, "mean",

    value: ->

        numeric = this.numeric()

        if not numeric.empty()

            return numeric.sum() / numeric.length

        else

            return null

    configurable: false,
    enumerable: false,
    writable: false

Object.defineProperty Array.prototype, "median",

    value: ->

        numeric = this.numeric().sort()

        if not numeric.empty()

            low = numeric[ Math.floor (numeric.length - 1) / 2 ]
            high = numeric[ Math.ceil (numeric.length - 1) / 2 ]

            return (low + high) / 2

        else

            return null

    configurable: false,
    enumerable: false,
    writable: false

Object.defineProperty Array.prototype, "mode",

    value: (counts = false) ->

        numeric = this.numeric()

        if not numeric.empty()

            tally = {}

            for element in numeric

                if tally[element] is undefined then tally[element] = 0

                tally[element] += 1

            if counts then return tally

            max = Object.values(tally).max()

            return Object.keys(tally).filter((element) => tally[element] is max).map Number

        else

            return null

    configurable: false,
    enumerable: false,
    writable: false

# Credit: https://stackoverflow.com/a/10757602/1544937
# Credit: https://stackoverflow.com/a/20070691/1544937
Object.defineProperty Array.prototype, "unique",

    value: ->

        Array.from new Set this

    configurable: false,
    enumerable: false,
    writable: false

# Credit: https://stackoverflow.com/a/53606357/1544937
Object.defineProperty Array.prototype, "subset",

    value: (array = []) ->

        this.every (item) -> array.includes item

    configurable: false,
    enumerable: false,
    writable: false

# Credit: https://stackoverflow.com/a/24137301/1544937
Object.defineProperty Array.prototype, "random",

    value: ->

        this[ Math.floor(Math.random() * this.length) ]

    configurable: false,
    enumerable: false,
    writable: false

# Credit: https://stackoverflow.com/a/70669834/1544937
Object.defineProperty Array.prototype, "numeric",

    value: (cast = true) ->

        numeric = this.filter (item) -> /^-?\d+\.?\d*$/.test item

        return if cast then numeric.map Number else numeric

    configurable: false,
    enumerable: false,
    writable: false

# Credit: https://stackoverflow.com/a/57067151/1544937
Object.defineProperty Array.prototype, "exclude",

    value: (condition, item) ->

        count = 0

        for element, index in this

            if not condition.call item, element, index, this

                if index isnt count

                    this[count] = element

                count++

        this.length = count

        return this

    configurable: false,
    enumerable: false,
    writable: false

array.js

// Info: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/defineProperty
// Info: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array
// Source: https://gist.github.com/jgphilpott/a1367ca419ac2807ed4340d69356b7f1

Object.defineProperty(Array.prototype, "first", {
  value: function() {
    return this.at(0);
  },
  configurable: false,
  enumerable: false,
  writable: false
});

Object.defineProperty(Array.prototype, "last", {
  value: function() {
    return this.at(-1);
  },
  configurable: false,
  enumerable: false,
  writable: false
});

Object.defineProperty(Array.prototype, "clear", {
  value: function() {
    return this.length = 0;
  },
  configurable: false,
  enumerable: false,
  writable: false
});

Object.defineProperty(Array.prototype, "empty", {
  value: function() {
    return this.length === 0;
  },
  configurable: false,
  enumerable: false,
  writable: false
});

Object.defineProperty(Array.prototype, "boolean", {
  value: function() {
    return Boolean(this.length);
  },
  configurable: false,
  enumerable: false,
  writable: false
});

Object.defineProperty(Array.prototype, "number", {
  value: function() {
    return Number(this);
  },
  configurable: false,
  enumerable: false,
  writable: false
});

Object.defineProperty(Array.prototype, "string", {
  value: function() {
    return String(this);
  },
  configurable: false,
  enumerable: false,
  writable: false
});

Object.defineProperty(Array.prototype, "array", {
  value: function() {
    return Array(this);
  },
  configurable: false,
  enumerable: false,
  writable: false
});

Object.defineProperty(Array.prototype, "object", {
  value: function() {
    return Object(this);
  },
  configurable: false,
  enumerable: false,
  writable: false
});

Object.defineProperty(Array.prototype, "sum", {
  value: function() {
    var numeric;
    numeric = this.numeric();
    if (!numeric.empty()) {
      return numeric.reduce(function(a, b) {
        return a + b;
      });
    } else {
      return 0;
    }
  },
  configurable: false,
  enumerable: false,
  writable: false
});

Object.defineProperty(Array.prototype, "difference", {
  value: function() {
    var numeric;
    numeric = this.numeric();
    if (!numeric.empty()) {
      return numeric.reduce(function(a, b) {
        return a - b;
      });
    } else {
      return 0;
    }
  },
  configurable: false,
  enumerable: false,
  writable: false
});

Object.defineProperty(Array.prototype, "product", {
  value: function() {
    var numeric;
    numeric = this.numeric();
    if (!numeric.empty()) {
      return numeric.reduce(function(a, b) {
        return a * b;
      });
    } else {
      return 0;
    }
  },
  configurable: false,
  enumerable: false,
  writable: false
});

Object.defineProperty(Array.prototype, "quotient", {
  value: function() {
    var numeric;
    numeric = this.numeric();
    if (!numeric.empty()) {
      return numeric.reduce(function(a, b) {
        return a / b;
      });
    } else {
      return 0;
    }
  },
  configurable: false,
  enumerable: false,
  writable: false
});

Object.defineProperty(Array.prototype, "min", {
  value: function(numeric = true) {
    if (numeric) {
      return Math.min.apply(null, this.numeric());
    } else {
      return this.sort().first();
    }
  },
  configurable: false,
  enumerable: false,
  writable: false
});

Object.defineProperty(Array.prototype, "max", {
  value: function(numeric = true) {
    if (numeric) {
      return Math.max.apply(null, this.numeric());
    } else {
      return this.sort().last();
    }
  },
  configurable: false,
  enumerable: false,
  writable: false
});

Object.defineProperty(Array.prototype, "absMin", {
  value: function(numeric = true) {
    if (numeric) {
      return Math.min.apply(null, this.numeric().map(Math.abs));
    } else {
      return this.sort().first();
    }
  },
  configurable: false,
  enumerable: false,
  writable: false
});

Object.defineProperty(Array.prototype, "absMax", {
  value: function(numeric = true) {
    if (numeric) {
      return Math.max.apply(null, this.numeric().map(Math.abs));
    } else {
      return this.sort().last();
    }
  },
  configurable: false,
  enumerable: false,
  writable: false
});

Object.defineProperty(Array.prototype, "mean", {
  value: function() {
    var numeric;
    numeric = this.numeric();
    if (!numeric.empty()) {
      return numeric.sum() / numeric.length;
    } else {
      return null;
    }
  },
  configurable: false,
  enumerable: false,
  writable: false
});

Object.defineProperty(Array.prototype, "median", {
  value: function() {
    var high, low, numeric;
    numeric = this.numeric().sort();
    if (!numeric.empty()) {
      low = numeric[Math.floor((numeric.length - 1) / 2)];
      high = numeric[Math.ceil((numeric.length - 1) / 2)];
      return (low + high) / 2;
    } else {
      return null;
    }
  },
  configurable: false,
  enumerable: false,
  writable: false
});

Object.defineProperty(Array.prototype, "mode", {
  value: function(counts = false) {
    var element, i, len, max, numeric, tally;
    numeric = this.numeric();
    if (!numeric.empty()) {
      tally = {};
      for (i = 0, len = numeric.length; i < len; i++) {
        element = numeric[i];
        if (tally[element] === void 0) {
          tally[element] = 0;
        }
        tally[element] += 1;
      }
      if (counts) {
        return tally;
      }
      max = Object.values(tally).max();
      return Object.keys(tally).filter((element) => {
        return tally[element] === max;
      }).map(Number);
    } else {
      return null;
    }
  },
  configurable: false,
  enumerable: false,
  writable: false
});

// Credit: https://stackoverflow.com/a/10757602/1544937
// Credit: https://stackoverflow.com/a/20070691/1544937
Object.defineProperty(Array.prototype, "unique", {
  value: function() {
    return Array.from(new Set(this));
  },
  configurable: false,
  enumerable: false,
  writable: false
});

// Credit: https://stackoverflow.com/a/53606357/1544937
Object.defineProperty(Array.prototype, "subset", {
  value: function(array = []) {
    return this.every(function(item) {
      return array.includes(item);
    });
  },
  configurable: false,
  enumerable: false,
  writable: false
});

// Credit: https://stackoverflow.com/a/24137301/1544937
Object.defineProperty(Array.prototype, "random", {
  value: function() {
    return this[Math.floor(Math.random() * this.length)];
  },
  configurable: false,
  enumerable: false,
  writable: false
});

// Credit: https://stackoverflow.com/a/70669834/1544937
Object.defineProperty(Array.prototype, "numeric", {
  value: function(cast = true) {
    var numeric;
    numeric = this.filter(function(item) {
      return /^-?\d+\.?\d*$/.test(item);
    });
    if (cast) {
      return numeric.map(Number);
    } else {
      return numeric;
    }
  },
  configurable: false,
  enumerable: false,
  writable: false
});

// Credit: https://stackoverflow.com/a/57067151/1544937
Object.defineProperty(Array.prototype, "exclude", {
  value: function(condition, item) {
    var count, element, i, index, len, ref;
    count = 0;
    ref = this;
    for (index = i = 0, len = ref.length; i < len; index = ++i) {
      element = ref[index];
      if (!condition.call(item, element, index, this)) {
        if (index !== count) {
          this[count] = element;
        }
        count++;
      }
    }
    this.length = count;
    return this;
  },
  configurable: false,
  enumerable: false,
  writable: false
});

Prototyping

This gist is part of a collection of gists that extend JavaScript data prototypes such as Boolean, Number, String, Array and Object. See below for links to all the gists:

• Boolean
• Number
• String
• Array
• Object