Method Array.randomize

Randomize elements in an array

• Syntax undefined Array.randomize([ Boolean ru ])
  
  Reorders the elements in the array in-place in a random order. Elements which have the value of undefined are automatically arranged last if ru (randomize undefined) is not true.
• Parameters

  Boolean ru (Optional)

  Set to true if you want to randomize undefined values.

• Return value No explicit return value. Default value of undefined is returned.
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  Unless otherwise noted all code in the JSLab Standard Library is licensed as GPLv3. See http://www.gnu.org/licenses/gpl.html for the entire license.

  // ************************************************************************** // Copyright 2007 - 2009 Tavs Dokkedahl // Contact: http://www.jslab.dk/contact.php // // This file is part of the JSLab Standard Library (JSL) Program. // // JSL is free software; you can redistribute it and/or modify // it under the terms of the GNU General Public License as published by // the Free Software Foundation; either version 3 of the License, or // any later version. // // JSL is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // // You should have received a copy of the GNU General Public License // along with this program. If not, see <http://www.gnu.org/licenses/>. // *************************************************************************** // Randomize elements in an array Array.prototype.randomize = function(ru) { if (!ru) this.sort(function(){return ((Math.random() * 3) | 0) - 1;}); else { var a = [].concat(this); var l = this.length; var al = n = 0; for(var i=0; i<l; i++) { al = a.length; // Get random integer in [0,a.length-1] n = Math.floor((Math.random() * al)); // Copy random element from a to this this[i] = a[n]; // If n was last element in a just pop a[n] if (n == al - 1) a.pop(); // Else copy last element from a to n and pop last element from a else { a[n] = a[al - 1]; a.pop(); } } } };