php数组找数有关问题

php数组找数问题？
$str ="1,2,3,4,5,6,0",$str1 ="1,3,5"如何找出str1中没有的数啊如$str2 ="2,4,6,0"

------解决方案--------------------

PHP code

$diffArr=array_diff(explode(',',$str),explode(',',$str1));  //求差集
echo implode("," , $diffArr); //输出