platypusrex

function reverseString(str) {
  return str.split('').reverse().join('');
}

reverseString('hello');

platypusrex

function palindrome(str) {
  return str.replace(/\W|_/gi, '').toLowerCase() === str.split('').reverse().join().replace(/\W|_/gi, '').toLowerCase() ? true : false;
}

palindrone('race car');

platypusrex

function factorialize(num) {
  if(num === 0){
    return 1;
  }
  return num * factorialize(num - 1);
}

factorialize(5);

platypusrex

function add() {
    if(arguments.length > 1){
        return Array.from(arguments).every(function(val){
            return typeof val === 'number';	
        }) ? Array.from(arguments).reduce(function(prev, current){
            return prev + current
        }) : undefined;
    }else if(typeof arguments[0] === 'number'){
        var x = arguments[0];
    	return function(y){

platypusrex

function binaryAgent(str) {
  return str.split(' ').map(function(val){
    return String.fromCharCode(parseInt(val, 2));
  }).join('').replace(',', ' ');
}

binaryAgent("01000001 01110010 01100101 01101110 00100111 01110100 00100000 01100010 01101111 01101110 01100110 01101001 01110010 01100101 01110011 00100000 01100110 01110101 01101110 00100001 00111111");

platypusrex

function sumPrimes(num) {
  return Array.apply(0, Array(num + 1))
    .map(function(x, y){
      return y 
  }).filter(function (i){
      return (i > 1) && Array
          .apply(0, Array(1 + ~~Math.sqrt(i)))
      .every(function(x, y){ 			
          	return (y < 2) || (i % y !== 0) 
      });

platypusrex

function steamroller(arr) {
  // I'm a steamroller, baby
  arr = Array.prototype.concat.apply([], arr);
  return arr.some(Array.isArray) ? steamroller(arr) : arr;
}

steamroller([1, [2], [3, [[4]]]]);

platypusrex

function unite(arr1, arr2, arr3) {
   return Array.from(arguments).reduce(function(a, b){
  	return a.concat(b).filter(function(val,pos,arr){
      return arr.indexOf(val) === pos;
    });
  });
}

unite([1, 2, 3], [5, 2, 1, 4], [2, 1], [6, 7, 8]);

platypusrex

function diff(arr1, arr2) {
  return newArr = arr1.filter(function(val){
    return arr2.indexOf(val) === -1;
  }).concat(arr2.filter(function(val){
    return arr1.indexOf(val) === -1;
  }));
}

diff(['diorite', 'andesite', 'grass', 'dirt', 'pink wool', 'dead shrub'], ['diorite', 'andesite', 'grass', 'dirt', 'dead shrub']);

platypusrex

function titleCase(str) {
  return str.split(' ').map(function(val){
  	return val.charAt(0).toUpperCase() + val.slice(1).toLowerCase();
    }).join(' ');
}

titleCase("sHoRt AnD sToUt");