title: laravel route variables passing null values give url error
body: <p>I have a route that <strong>has 3 optional</strong> variables declared as null in Controller</p>
  
  <pre><code>Route::get('gegonota/{gid?}/{cid?}/{nid?}', [
  'uses' =&gt; 'GegonosController@index', 
  'as' =&gt; 'gegonota'
  ]);
  </code></pre>
  
  <p>and <strong>even i change the order of the parameter the problem still exists.</strong></p>
  
  <pre><code>public function index($gid = null, $cid = null, $nid = null)
  </code></pre>
  
  <p>When values of the variables are null are not showing in the url like </p>
  
  <pre><code>http://localhost:8000/gegonota///1
  </code></pre>
  
  <p>and gives me route errors like it didnt find the specific url.</p>
  
  <p>I have to check and substitute null to 0 so that has something in the url and  give no error.
  Which is laravel way to do that avoiding all the trouble.
  thanks</p>