PHP array_diff application

array_diff () calculates the difference array sets.

array_diff (array $ array1, array $ array2 [, array $ ...]), compare array1 and one or more other array, return values ​​of array1 but not in the other array, that keys are preserved.

Two things to note:

1. Only two element values ​​(string) $ elem1 === (string) $ elem2 when considered identical.

2. Check only one-dimensional multi-dimensional array can be used array_diff ($ array1 [0], $ array2 [0]) check deeper dimension.

Here's an example of official website.

<?php
$array1 = array("a" => "green", "red", "blue", "red");
$array2 = array("b" => "green", "yellow", "red");
$result = array_diff($array1, $array2);

print_r($result);
?>

The output is:

Array
(
    [1] => blue
)