title: GetStringUTFChars function parameter
body: <p>I'm developing Android app using jni.<br>
  And I used GetStringUTFChars function as follows</p>
  
  <pre><code>jboolean iscopy;
  const char* trainfile = (env)-&gt;GetStringUTFChars(jstr, &amp;iscopy);
  </code></pre>
  
  <p>But I saw another example like this</p>
  
  <pre><code>const char *inCStr = (*env)-&gt;GetStringUTFChars(env, inJNIStr, NULL);
  </code></pre>
  
  <p>Both works well. But I cannot find any documentation about the former grammer even that is more concise. </p>
  
  <p>Where Can I find the documentation, and Is there any difference between them?</p>