title: NSString convert string to NSData using encoding
body: <p>I have got small issue in my app.</p>
  
  <p>I make NSMutableURLRequest and send body to my webserice.</p>
  
  <pre><code>jsonRequest = @"{\"s\":\"deón\"}";
  
  NSData *requestData = [NSData dataWithBytes:[jsonRequest UTF8String] length:[jsonRequest length]];
  </code></pre>
  
  <p>I need change "ó" symbol to \u00F3.</p>
  
  <p>Any idea?</p>