Freecodecamp code snippets.md

Bonfire section

Reverse a string str:

str.split().reverse().join();

Factorialize a number:

Return the factorial of the integer n

var arr = Array.apply(null, Array(num)).map(function(a, b) {return b +1;});
factorial = arr.reduce(function(prod, n) {return prod * n}, 1);

Check for palindromes in string str:

var s = str.toLowerCase().replace(/ /g, '').replace(/[^a-z0-9]+/g, '');
var rev = s.split('').reverse().join('');
return rev === s;

Find the longest word in a string str:

var arr = str.split(' ');
var max = 0;
arr.map(function(a){if (a.length > max){max = a.length; str = a};});
return str.length;

Title case a sentence:

var s = str.toLowerCase().split(' ');
var cap = [];
s.map(function(word){cap = cap.concat(word.replace(word.charAt(0), word.charAt(0).toUpperCase()));});
str = cap.join(' ');
return str;

Return largest numbers in arrays:

Return an array consisting of the largest number from each provided sub-array

arr.map(function(a){return Math.max.apply(Math, a)});

Confirm the ending:

Check if a string str ends with the given target string

str = target === str.substr(- target.length);

Repeat a string:

Repeat a given string str n times. Return an empty string if n is a negative number

if(num > 1){
  str = str.repeat(num);
} else {
  str = '';
}

Truncate a string:

Truncate a string str if it is longer than maximum string length. Return the truncated string with a "..." ending.

  if(num >= str.length){
    str;
  } else if(num <= 3){
    str = str.slice(0,num).concat('...');
  } else {
    str = str.slice(0,num-3).concat('...');
  }

Chunky monkey:

Split an array arr into groups the length of size and return them as a multidimensional array.

  var new_arr = [];
  var repeats = Math.ceil(arr.length / size);
  for (var i = 0; i < repeats; i++) {
    new_arr.push(arr.splice(0,size));    
  }

Slasher Flick:

Return the remaining elements of an array after chopping off n elements from the head.

arr.splice(0,n);

Mutations:

Return true if the string in the first element of the array contains all of the letters of the string in the second element of the array.

  var s = arr[0].toLowerCase();
  var wordArray = arr[1].toLowerCase().split('');

  for (i = 0; i < wordArray.length; i++) { 
    if (s.indexOf(wordArray[i]) === -1) { 
      arr = false;
      break;
    } else {
      arr = true;
    }
  };

Falsy Bouncer:

Remove all falsy values from an array. Falsy values in javascript are false, null, 0, "", undefined, and NaN.

  arr = arr.filter(function(n){ 
    n = new Boolean(n); 
    return n.toString() === 'true';
  })

Seek and Destroy:

Given an initial array arr followed by one or more arguments, remove all elements from arr that are of the same value as these arguments.

  var args = Array.prototype.slice.call(arguments);
  arr = args.shift();
  for(i=0; i < args.length; i++) {
    arr = arr.filter(function(a){ return a !== args[i]});
  }

Where do I belong:

Return the lowest index at which a value (second argument) should be inserted into a sorted array (first argument).

  arr.push(num);
  console.log(arr);
  arr = arr.sort(function(a,b){ return a - b });
  console.log(arr);
  return arr.indexOf(num);