The array_diff() function compares array values, and returns the differences. It returns an array containing the entries from the first array that are not present in any of the other arrays.
Syntax
array_diff(arr1, arr2, arr3, arr4, …)
Parameters
arr1 − Array to compare from. Required.
arr2 − Array to compare against. Required.
arr3 − You can add more arrays to compare. Optional.
arr4 − You can add more arrays to compare. Optional.
Return
The array_diff() function returns an array containing the entries from the first array that are not present in any of the other arrays.
Example
<?php
$arr1=array("p"=>"steve","q"=>"david","r"=>"peter");
$arr2=array("s"=>"steve","t"=>"amy");
$res = array_diff($arr1,$arr2);
print_r($res);
?>
Output
Array ( [q] => david [r] => peter )