title: How can I define comparison has to be an int?
body: <p>Here a short code for the thing which is already coded:</p>
  
  <pre><code>if (str.Length % 3 != 0)
  </code></pre>
  
  <p>Now my question is, how can I define, that if <code>str.Length % 3 = int</code> it has to do something?</p>
  
  <p>Here an example: </p>
  
  <p><code>123456789123 / 3 = int...</code></p>
  
  <p>I know, the Syntax I used isn't correct, but it's because I don't know how to do it.
  You would also help me, if you told me, what the "opposite" of  <code>if (str.Length % 3 != 0)</code> is.</p>
  
  <p>Thanks for helping.</p>