PHP array diff key

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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

Pictorial Presentation :

php array array_diff_key() function

Example :

  1. $array1 = array('Math'=>77, 20, 'Geography'=>89, 'Language'=>67);  

  2. $array2 = array('Language'=>71, 'Science'=>91 ,20, 'Geography'=>89);  

  3. var_dump(array_diff_key($array1, $array2));  

  4. ?>  

Output :

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