What does !1 and !0 mean in Javascript?
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/8255653/return-1-in-javascript">return !1 in javascript</a>  </p>
</blockquote>



<p>In a JavaScript file I had to read today, there was a line where a variable was declared like a factorial, like this :</p>

<pre><code>var myVariable = !1;
</code></pre>

<p>and then something similar was used as parameter in a function like this :</p>

<pre><code>return variable.myFunction(!0);
</code></pre>

<p>Can anyone explain me what the exclamation mark means in this context and eventually, why this is generally used for (benefits) ?</p>

<p>Thank you in advance !</p>
