<?php
Class Str{

    public static function clean($string){

        $string = str_replace(' ', '-', $string); // Replaces all spaces with hyphens.
        $string = preg_replace('/[^A-Za-z0-9\-]/', '', $string); // Removes special chars.

        return preg_replace('/-+/', '-', $string); // Replaces multiple hyphens with single one.

    }

}