title: PHP preg_match car license plate
body: <p>So I just learned about preg_match in PHP the other day and now i'm trying to preg_match a license plate. It should check for this:</p>
  
  <p><code>9a-4e-yy</code>, so a <code>-</code> and before and after that numbers or letters and then a <code>-</code> again and more numbers or letters. But it has to be exactly 2 numbers or letters next to each other, not more.</p>
  
  <p>For now I have this code:</p>
  
  <pre><code>return preg_match("/^([0-9])"."([0-9])"."(\-([0-9])"."([0-9]))"."(\-([0-9])"."([0-9]))$/", $kenteken );
  </code></pre>
  
  <p>But that only checks on numbers.</p>
  
  <p>I hope you guys could help me to get it work with letters too.</p>
  
  <p>Thanks in advance!</p>