Computes the difference of arrays using keys for comparison

# array_diff_key

(PHP 5 >= 5.1.0, PHP 7)

array_diff_key — Computes the difference of arrays using keys for comparison

### Descrierea

array_diff_key ( array `$array1` , array `$array2` [, array `$...` ] ) : 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.

### Parametri

`array1`

  The array to compare from

`array2`

  An array to compare against

`...`

  More arrays to compare against

### Valorile întoarse

Returns an array containing all the entries from `array1` whose keys are absent from all of the other arrays.

### Exemple

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);
$array2 = array('green' => 5, 'yellow' => 7, 'cyan' => 8);
var_dump(array_diff_key($array1, $array2));
?>`

Exemplul de mai sus va afișa:

    array(3) {
      ["blue"]=>
      int(1)
      ["red"]=>
      int(2)
      ["purple"]=>
      int(4)
    }

`<?php
$array1 = array('blue' => 1, 'red' => 2, 'green' => 3, 'purple' => 4);
$array2 = array('green' => 5, 'yellow' => 7, 'cyan' => 8);
$array3 = array('blue' => 6, 'yellow' => 7, 'mauve' => 8);
var_dump(array_diff_key($array1, $array2, $array3));
?>`

Exemplul de mai sus va afișa:

    array(2) {
      ["red"]=>
      int(2)
      ["purple"]=>
      int(4)
    }

### Note

> Notă:

> 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]);.

### A se vedea și

- array_diff() - Calculează diferența dintre tablouri
- array_udiff() - Computes the difference of arrays by using a callback function for data comparison
- array_diff_assoc() - Computes the difference of arrays with additional index check
- array_diff_uassoc() - Computes the difference of arrays with additional index check which is performed by a user supplied callback function
- array_udiff_assoc() - Computes the difference of arrays with additional index check, compares data by a callback function
- array_udiff_uassoc() - Computes the difference of arrays with additional index check, compares data and indexes by a callback function
- array_diff_ukey() - Computes the difference of arrays using a callback function on the keys for comparison
- array_intersect() - Computes the intersection of arrays
- array_intersect_assoc() - Computes the intersection of arrays with additional index check
- array_intersect_uassoc() - Computes the intersection of arrays with additional index check, compares indexes by a callback function
- array_intersect_key() - Computes the intersection of arrays using keys for comparison
- array_intersect_ukey() - Computes the intersection of arrays using a callback function on the keys for comparison