shuffle.php

<?php
// http://www.php.net/shuffle
//http://www.cnblogs.com/Jerry-Chou/archive/2012/01/04/2311610.html
function sh($arr){
  $n=count($arr);
  while($n>1){
	$n--;
	$k=rand(0,$n);
	$tmp=$arr[$n];
	$arr[$n]=$arr[$k];
	$arr[$k]=$tmp;
  }
 
}

$arr=array(1,2,3,4);
sh(&$arr);
print_r($arr);