phpjs/functions/array/shuffle.js

php.js offers community built php functions in javascript

function shuffle(inputArr) {
  // From: http://phpjs.org/functions
  // +   original by: Jonas Raoni Soares Silva (http://www.jsfromhell.com)
  // +    revised by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
  // +    revised by: Brett Zamir (http://brett-zamir.me)
  // +   improved by: Brett Zamir (http://brett-zamir.me)
  // %        note 1: This function deviates from PHP in returning a copy of the array instead
  // %        note 1: of acting by reference and returning true; this was necessary because
  // %        note 1: IE does not allow deleting and re-adding of properties without caching
  // %        note 1: of property position; you can set the ini of "phpjs.strictForIn" to true to
  // %        note 1: get the PHP behavior, but use this only if you are in an environment
  // %        note 1: such as Firefox extensions where for-in iteration order is fixed and true
  // %        note 1: property deletion is supported. Note that we intend to implement the PHP
  // %        note 1: behavior by default if IE ever does allow it; only gives shallow copy since
  // %        note 1: is by reference in PHP anyways
  // *          test: skip
  // *     example 1: ini_set('phpjs.strictForIn', true);
  // *     example 2: var data = {5:'a', 2:'3', 3:'c', 4:5, 'q':5};
  // *     example 1: shuffle(data);
  // *     example 1: $result = data;
  // *     returns 1: {5:'a', 4:5, 'q':5, 3:'c', 2:'3'}
  // *     example 2: ini_set('phpjs.strictForIn', true);
  // *     example 2: var data = {5:'a', 2:'3', 3:'c', 4:5, 'q':5};
  // *     example 2: shuffle(data);
  // *     example 2: $result = data;
  // *     returns 2: {5:'a', 'q':5, 3:'c', 2:'3', 4:5}
  var valArr = [],
      k = '',
      i = 0,
      strictForIn = false,
      populateArr = [];

  for (k in inputArr) { // Get key and value arrays
    if (inputArr.hasOwnProperty(k)) {
      valArr.push(inputArr[k]);
      if (strictForIn) {
        delete inputArr[k];
      }
    }
  }
  valArr.sort(function() {
    return 0.5 - Math.random();
  });

  // BEGIN REDUNDANT
  this.php_js = this.php_js || {};
  this.php_js.ini = this.php_js.ini || {};
  // END REDUNDANT
  strictForIn = this.php_js.ini['phpjs.strictForIn'] && this.php_js.ini['phpjs.strictForIn'].local_value && this.php_js.ini['phpjs.strictForIn'].local_value !== 'off';
  populateArr = strictForIn ? inputArr : populateArr;

  for (i = 0; i < valArr.length; i++) { // Repopulate the old array
    populateArr[i] = valArr[i];
  }

  return strictForIn || populateArr;
}