如何在PHP中比较数组的加减法?

array_diff()

<?php

$currentArr = ['apples','oranges','pears','test'];
$newArr = ['apples','oranges','pears', 'grapes'];

$removed = array_diff($currentArr, $newArr);
print_r($removed);
// output: 
// Array ( [3] => test )

// switch the order to get the added items:
$added = array_diff($newArr, $currentArr);
print_r($added);
// output:
// Array ( [3] => grapes )

$removed = array_diff($currentAr,$newArr);
$added = array_diff($newArr,$currentAr);