title: Reversing a BOOL
body: <p>In objective-c, if I wanted to reverse the value of a <code>BOOL</code>, would this work, or would it set the value of the <code>BOOL</code> to <code>NO</code>?</p>
  
  <pre><code>BOOL ab = YES;
  
  ab = !ab; // would this reverse the BOOL, ab, and set it to NO?
  
  if (ab == NO) {
      ab = !ab; // would this reverse the BOOL again and set it to YES?
  }
  </code></pre>