title: How to make a final variable in PHP?
body: <p>I can't find out, or maybe I am thinking wrongly but I need to make a variable that can't be changed, like read-only, something like :</p>
  
  <pre><code>final $finalVar = 'extremely secret number'; // don't change
  
  $finalVar = 'hacked...'; // THROW I GIANT BIG ERROR HERE !
  </code></pre>