PHP比較兩個數組的差異

array_diff($arr, $arr1);

//比較數組差異
$arr = [1,2,3,4];

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

//打印輸出如下，函數第二個參數為參數值，沒有差異則返回空數組
array(1) {
  [3] => int(4)
}