(PHP 4 >= 4.3.0, PHP 5, PHP 7, PHP 8)
array_diff_assoc — Computes the difference of arrays with additional index check
Compares array against arrays and returns the difference. Unlike array_diff() the array keys are also used in the comparison.
arrayThe array to compare from
arraysArrays to compare against
Returns an array containing all the values from array that are not present in any of the other arrays.
| Version | Description |
|---|---|
| 8.0.0 | This function can now be called with only one parameter. Formerly, at least two parameters have been required. |
Example #1 array_diff_assoc() example
In this example the "a" => "green" pair is present in both arrays and thus it is not in the output from the function. Unlike this, the pair 0 => "red" is in the output because the key of "red" is automatically assigned to 0 in the first array, whereas it is assigned to 1 in the second array as the key 0 is already taken by yellow.
<?php
$array1 = array("a" => "green", "b" => "brown", "c" => "blue", "red");
$array2 = array("a" => "green", "yellow", "red");
$result = array_diff_assoc($array1, $array2);
print_r($result);
?>The above example will output:
Array ( [b] => brown [c] => blue [0] => red )
Example #2 array_diff_assoc() example
Two values from key => value pairs are considered equal only if (string) $elem1 === (string) $elem2 . In other words a strict check takes place so the string representations must be the same.
<?php
$array1 = array(0, 1, 2);
$array2 = array("00", "01", "2");
$result = array_diff_assoc($array1, $array2);
print_r($result);
?>The above example will output:
Array ( [0] => 0 [1] => 1 )
Note: This function only checks one dimension of an n-dimensional array. It is possible to check deeper dimensions by using, for example,
array_diff_assoc($array1[0], $array2[0]);.
Note: Ensure arguments are passed in the correct order when comparing similar arrays with more keys. The new array should be the first in the list.