php数组找数问题？

Question

$str ="1,2,3,4,5,6,0",$str1 ="1,3,5"如何找出str1中没有的数啊如$str2 ="2,4,6,0"

Answer 1

$a=array_diff(explode(',',$str),explode(',',$str1));
echo join($a,',');

Answer 2

将$str1和$str 转换为数组,通过 array_diff()函数求出他们的差价集！  

Answer 3

将str和str1转为数组后按上面操作

Answer 4

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