array_diff_key
(PHP 5 >= 5.1.0RC1)
array_diff_key -- Computes the difference of arrays using keys for comparison
Description
array
array_diff_key ( array array1, array array2 [, array ...] )
Compares the keys from array1 against the keys
from array2 and returns the difference.
This function is like array_diff() except the
comparison is done on the keys instead of the values.
Parameters
array1
The array to compare from
array2
An array to compare against
...
More arrays to compare against
Return Values
Returns an array containing all the entries from
array1 that are not present in any of the other arrays.
Examples
Example 1. array_diff_key() example
The two keys from the key => value pairs are
considered equal only if
(string) $key1 === (string) $key2 . In other words
a strict type check is executed so the string representation must be
the same.
<?php
$array1 = array('blue' => 1, 'red' => 2, 'green' => 3, 'purple' => 4);
$array2 = array('green' => 5, 'blue' => 6, 'yellow' => 7, 'cyan' => 8);
var_dump(array_diff_key($array1, $array2));
?>
|
The above example will output: array(2) {
["red"]=>
int(2)
["purple"]=>
int(4)
} |
|
Notes
Note:
This function only checks one dimension of a n-dimensional
array. Of course you can check deeper dimensions by using
array_diff_key($array1[0], $array2[0]);.