Quick Reference
The PHP array_diff_key() function compares the keys of two or more arrays, and returns an array of entries from array1 not in the other array(s).
Only the keys are compared. Not the values.
<?php
$a1 = array('Car 1' => 'Lamborghini', 'Car 2' => 'Ferrari', 'Car 5' => 'Maserati');
$a2 = array('Car 1' => 'Lamborghini', 'Car 2' => 'Ferrari', 'Car 3' => 'Maserati');
$result = array_diff_key($a1, $a2);
print_r($result);
?>Note
Arrays count starting from zero NOT one. So item 1 is position [0], item 2 is position [1], and item 3 is position [2] … and so on.
Output
Array ( [Car 5] => Maserati )Syntax
array_diff_key(array1, array2, array3, ...)Parameters
| Parameter | Description |
|---|---|
| array1 | The array to compare from (required) |
| array2 | The array to compare against (required) |
| array3, ... | Additional arrays to compare against |
PHP Notes:
- When using PHP, single or double quotation marks are acceptable and work identically to one another; choose whichever you prefer, and stay consistent
- Arrays count starting from zero NOT one; so item 1 is position [0], item 2 is position [1], and item 3 is position [2] … and so on
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