title: NSUserDefaults synchronize-method
body: <pre><code> NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
  [defaults setObject:@"xxxxxxxx" forKey:@"name"];
  
  [defaults synchronize];
  </code></pre>
  
  <p>I need to know why do i have to use the last line of the above code <code>[defaults synchronize]</code> ? What is the purpose of using it? Is it a must ?</p>