PHP - array_intersect_key

array_intersect_key

(PHP 5> = 5.1.0)

array_intersect_key - Computes the intersection of array by comparing by keys

description

array array_intersect_key ( array $ array1 , array $ array2 [, array $ ... ])

array_intersect_key () returns an array containing all the values ​​of array1 that have the same keys present in all arguments.

Parameters

array1

The array with keys to be checked.

array2

An array to compare keys.

array

A variable list of arrays for comparison.

Returned Value

Returns an associative array containing all the values ​​of array1 that are present in all arguments.

Examples

Example # 1 Example of array_intersect_key ()

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

The above example will print:

array (2) {
  ["blue"] =>
  int (1)
  ["green"] =>
  int (3)
}

In our example you can see that only the 'blue' and 'green' keys are present in both array and so returned. Also note that the values ​​of the 'blue' and 'green' keys differ in the two arrays. The combination occurs because only the keys are checked. The returned values ​​are from array1 .

The two keys of the key => value pair are considered equal only if (string) $ key1 === (string) $ key2 . In other words a type check is executed, then the string representation must be the same.