title: How do I check whether a string exists in an array?
body: <p>I have this code:</p>
  
  <pre><code>var
    ExtString: string;
  const
    Extensions : array[0..4] of string = ('.rar', '.zip', '.doc', '.jpg', '.gif');
  
  if ExtString in Extensions then
  </code></pre>
  
  <p>On the last line, I get an error:</p>
  
  <blockquote>
    <p>[DCC Error] E2015 Operator ('then') not applicable to this operand type</p>
  </blockquote>
  
  <p>I think I can not do this, so how can I properly perform my task?</p>