PHP switch structure that fills an array with default values up to a specific index

MagicSwitch.php

<?php
$params = array('users', 'JWhy', 'repositories');
$n_params = sizeof($params);

switch($n_params){
 case 0:
   die('Not enough information supplied');
   break;
 case 1:
   $params[1] = '';
   $n_params = 2;
 case 2:
   $params[2] = '';
   $n_params = 3;
 case 3:
   $params[3] = '';
   $n_params = 4;
 case 4:
   //handle_request($params);
   break;
}