PHP Manual: array_diff


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array_diff

(PHP 4 >= 4.0.1, PHP 5)

array_diff -- Computes the difference of arrays

Description

array array_diff ( array array1, array array2 [, array ...] )

Compares array1 against array2 and returns the difference.

Examples

Example 1. array_diff() example

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

print_r($result);
?>

Multiple occurrences in $array1 are all treated the same way. This will output :

Array
(
    [1] => blue
)

Notes

Note: Two elements are considered equal if and only if (string) $elem1 === (string) $elem2. In words: when the string representation is the same.

Note: This function only checks one dimension of a n-dimensional array. Of course you can check deeper dimensions by using array_diff($array1[0], $array2[0]);.

Warning

This was broken in PHP 4.0.4!