PHP array_diff() – Computing the Difference Between Arrays

The array_diff() function compares one or more arrays and returns the values from the first array that are not present in any of the other arrays.

Parameters array1 – The array to compare against the others. array2 – The array to compare with array1. ... – Optional additional arrays for comparison.

Return value

Returns an array containing all values from array1 that are not found in any of the other argument arrays, preserving the original keys.

Example

<?php
$array1 = array("a" => "green", "red", "blue", "red");
$array2 = array("b" => "green", "yellow", "red");
$result = array_diff($array1, $array2);
print_r($result);
?>

Output

Array
(
    [1] => blue
)