title: How to control the scientifc style of NSNumberFormatter?
body: <p>I'm converting a long string representing a very big or small number to a string in scientific notation. E.g. 9999999999999999999999999 to 9.999999999999999E24.</p>
  
  <p>I use NSNumberFormatter.</p>
  
  <pre><code>NSNumberFormatter *ns = [[NSNumberFormatter alloc] init];
  [ns setNumberStyle: NSNumberFormatterScientificStyle];
  NSString *result = [ns stringFromNumber: [ns numberFromString: aBigOrSmallString]];
  [ns release];
  </code></pre>
  
  <p>But how can I control the precision part? For example, from 912345678 to 9.12E8 or 9.1234E8.</p>