title: Objective-C: Convert the entire double value to string without losing data
body: <p>I have the following double value: <code>0.000900137869045636</code>
  which I would like to convert to a <code>NSString</code>.</p>
  
  <p>I've tried the following code, but no matter what, it rounds the value to this: <code>0.000900138</code></p>
  
  <pre><code>[NSString stringWithFormat:@"%.20lf", [currentLocation coordinate].latitude];
  </code></pre>
  
  <p>What should I do to keep the double number as it is?</p>
  
  <p>Thank you.</p>