ARRAY_DIFF_KEY(3) 1 ARRAY_DIFF_KEY(3)
array_diff_key - Computes the difference of arrays using keys for comparison
SYNOPSIS
array array_diff_key (array $array1, array $array2, [array $...])
DESCRIPTION
Compares the keys from $array1 against the keys from $array2 and returns the difference. This function is like array_diff(3) except the
comparison is done on the keys instead of the values.
PARAMETERS
o $array1
- The array to compare from
o $array2
- An array to compare against
o $...
- More arrays to compare against
RETURN VALUES
Returns an array containing all the entries from $array1 whose keys are not present in any of the other arrays.
EXAMPLES
Example #1
array_diff_key(3) 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]);.
SEE ALSO
array_diff(3), array_udiff(3), array_diff_assoc(3), array_diff_uassoc(3), array_udiff_assoc(3), array_udiff_uassoc(3), array_diff_ukey(3),
array_intersect(3), array_intersect_assoc(3), array_intersect_uassoc(3), array_intersect_key(3), array_intersect_ukey(3).
PHP Documentation Group ARRAY_DIFF_KEY(3)