KT-personal-website/app/Utils/Selected.php

<?php

namespace App\Utils;

class Selected {

    static function selected($var, $ref) {
        $testPostsPage = explode('/', $ref);
        if (isset($testPostsPage[1]) && $testPostsPage[1] === 'post') {
            $ref = '/posts';
        }
        if ($var === $ref) {
            return 'active';
        }
    }
}