title: if->return vs. if->else efficiency
body: <p>This may sound like a silly question, and I hesitated to post it, but still:
  if something needs to run only in a certain condition, which of these is more efficient:</p>
  
  <p><strong>A.</strong></p>
  
  <pre><code>if (condition) {
     // do
     // things...
  }
  </code></pre>
  
  <p><strong>B.</strong></p>
  
  <pre><code>if (!condition) { return; }
  // do
  // things...
  </code></pre>