Description
array
array_diff_key ( array array1, array array2 [, array ...] )
array_diff_key() returns an array
containing all the values of array1
that have keys that are not present in any of the other arguments.
Note that the associativity is preserved. This function is like
array_diff() except the comparison is done on the
keys instead of the values.
Example 1. array_diff_key() example
<?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)
} |
|
The two keys from the key => value pairs are
considered equal only if
(string) $key1 === (string) $key2 . In other words
a strict type check is executed so the string representation must be
the same.
Note:
Please note that this function only checks one dimension of a n-dimensional
array. Of course you can check deeper dimensions by using
array_diff_key($array1[0], $array2[0]);.
See also array_diff(),
array_udiff()
array_diff_assoc(),
array_diff_uassoc(),
array_udiff_assoc(),
array_udiff_uassoc(),
array_diff_ukey(),
array_intersect(),
array_intersect_assoc(),
array_intersect_uassoc(),
array_intersect_key() and
array_intersect_ukey().
