shuffle() function reshuffles the order of an array. Before the reshuffle, seeds need to be generated first.

<?PHP
	$arr=array(1,2,3,4,5,6,7,8,9);
    srand((double)microtime() * 10000);
	shuffle($arr);
	foreach($arr as $element) echo "$element, "; //1, 8, 5, 4, 3, 6, 7, 9, 2, 	
?>

If the array is an associative array, then the values will be reshuffled.

<?PHP
	$arr=array("apple"=>"carbon","rice"=>"carbon","nuts"=>"fat","meat"=>"protein");
	srand((double)microtime() * 10000);
	shuffle($arr);
	foreach($arr as $key=>$val) echo "$key, $val; "; //0, protein; 1, fat; 2, carbon; 3, carbon;  
?>