PHP array_intersect_key() Function

The PHP array_intersect_key() function compares keys of an array against one or more other arrays and returns all elements of the first array that are present in all the arguments.

The array_intersect() function is like this function except the comparison is done on the values instead of the keys.

Syntax

array_intersect_key(array, arrays)

Parameters

Return Value

Returns an array containing all the entries from array which have keys that are present in all the arguments.

Exceptions

NA.

Example:

The example below shows the usage of array_intersect_key() function.

<?php
$Arr1 = array("a"=>"Red",
              "b"=>"Red",
              "c"=>"Blue",
              "d"=>"Blue",
              "e"=>"Green");
$Arr2 = array("a"=>"Red", 
              "b"=>"Blue", 
              "c"=>"Green");

//comparing Arr1 against Arr2
$Arr1_intersect_Arr2 = array_intersect_key($Arr1, $Arr2);
print_r($Arr1_intersect_Arr2);
?>

The output of the above code will be:

Array
(
    [a] => Red
    [b] => Red
    [c] => Blue
)