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PHP : array_diff_key() function

PHP: Computes the difference of arrays using keys for comparison

The array_diff_key() function is used to compare the keys from an array against the keys from another array and returns the difference. This function is like array_diff() except the comparison is done on the keys instead of the values.

Version:

(PHP 4 and above)

Syntax:

array_diff(array1, array2, array3 ...)

Parameter:

Name Description Required /
Optional
Type
array1 The specified array which will be compared with other arrays. Required Array
array2 Compared with the first array. Required Array
array3 Compared with the second array. Optional Array

Return value:

An array containing all the entries from array1 whose keys are not present in any of the other arrays i.e. array2, array3 etc..

Value Type: Array

Example:

<?php
$array1 = array('Math'=>77, 20, 'Geography'=>89, 'Language'=>67);
$array2 = array('Language'=>71, 'Science'=>91 ,20, 'Geography'=>89);
var_dump(array_diff_key($array1, $array2));
?>

Output:

array(1){["Math"]=> int(77) }

Pictorial Presentation:

php function reference: array_diff_key() function

View the example in the browser

Practice here online:

See also

PHP Function Reference

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