1.8 KiB
1.8 KiB
knuth-shuffle
The Fisher-Yates (aka Knuth) shuffle for Browser and Node.js
The Fisher-Yates (Knuth) Shuffle
As Microsoft learned the hard way (see article below), function random() { return 0.5 - Math.random() } turns out to be no-so-random at all.
The fisher-yates shuffle is an algorithm so simple that not even IEEE floating point math can screw it up!
I put this on npm as knuth-shuffle because fisher-yates-shuffle
was just too long of a name and shuffle was already taken.
Browser Example
<script src="./knuth-shuffle.js"></script>
(function () {
'use strict';
var a = [2,11,37,42]
, b
;
// The shuffle modifies the original array
// calling a.slice(0) creates a copy, which is assigned to b
b = window.knuthShuffle(a.slice(0));
console.log(b);
}());
Node Example
npm install -S knuth-shuffle
(function () {
'use strict';
var shuffle = require('knuth-shuffle').knuthShuffle
, a = [2,11,37,42]
, b
;
// The shuffle modifies the original array
// calling a.slice(0) creates a copy, which is assigned to b
b = shuffle(a.slice(0));
console.log(b);
}());