array_unique()
function
Removes duplicate values from an array. Keys are preserved; use array_values() to re-index.
Syntax
array_unique(array $array): array
Example
php
<?php
$tags = ['php','laravel','php','mysql','laravel'];
$unique = array_values(array_unique($tags));
print_r($unique); // ['php','laravel','mysql']
// Fast lookup
$allowed = array_flip(['admin','editor','author']);
if (isset($allowed[$role])) { echo 'Allowed'; }