PHP比較兩個數組是否相同

2、元素的順序可以不同

4、元素的個數必須相同

排序法：

<?php

$a1=array("red","green","blue","yellow","yellow");
$a2=array("red","green","yellow","blue","yellow");

sort($a1);
sort($a2);
if($a1 == $a2){
    print_r('數組相同');
}
?>