title: Why this output? NSLog(@"%0.2f", 1.345); // output 1.34
body: <pre><code>**NSLog(@"%0.2f", 1.345); // output 1.34**
  NSLog(@"%0.2f", 1.3451);// output 1.35
  NSLog(@"%0.2f", round(1.345 * 100)/100.);//output 1.35
  </code></pre>
  
  <p>Why the first line output 1.34?!!</p>
  
  <p>=======================================</p>
  
  <p><strong>Updated:</strong></p>
  
  <pre><code>NSLog(@"%.2f", round([@"644.435" doubleValue] * 100) / 100); // output 644.43, 
  </code></pre>
  
  <p>but</p>
  
  <pre><code>NSLog(@"%.2f", round([@"6.435" doubleValue] * 100) / 100); // output 6.44? 
  </code></pre>
  
  <p>If I want to convert a NSString to keep two digit after the point, would you please advise how to convert?</p>