PHP比較兩個數組的差別

array_diff($arr, $arr1);

//比較數組差別
$arr = [1,2,3,4];

$arr1 = [1,2,3];
$diff = array_diff($arr, $arr1);
dump($diff);

//打印輸出以下，函數第二個參數爲參數值，沒有差別則返回空數組
array(1) {
  [3] => int(4)
}