php 求二维数组的差集答:arr1=array(array(1,2,3,4,5),array(6,7,8,9,10),array(11,12,13,14,15),array(16,17,18,19,20));arr2=array(array(1,2,3,4,5),array(11,12,13,14,15));arr3=array();foreach ($arr1 as $key => $value) { if(!in_array($value,$arr2)){ arr3[]=$value;}...