title: Why shouldn't I use System.out.println() in android
body: <p>In the <a href="http://source.android.com/source/code-style.html" rel="noreferrer">Android Open Source Project's code style</a>, it states that we shouldn't use <code>System.out.println()</code> but I don't understand why. Can anyone explain? What should I use to trace my app's log?</p>
  
  <p>Here's the line for reference:</p>
  
  <blockquote>
    <p><code>System.out.println()</code> (or <code>printf()</code> for native code) should never be used. <code>System.out</code> and <code>System.err</code> get redirected to <code>/dev/null</code>, so your print statements will have no visible effects. However, all the string building that happens for these calls still gets executed.</p>
  </blockquote>