title: NSString stringWithFormat can't add backslash
body: <p>I'm calling a webService using AFNetWorking and want to pass a parameter of this shape,</p>
  
  <p><strong>112212234234324@abcdefghi_def.ab\/AB</strong></p>
  
  <p>and to achieve that i'm using following code,</p>
  
  <pre><code>@{@"someKey":[NSString stringWithFormat:@"%@@%@\/AB", someTextField.text, [aDictionary objectForKey:@"someOtherKey"]]};
  </code></pre>
  
  <p>But stringWithFormat is ignoring backslash and value for someKey is,</p>
  
  <p><strong>112212234234324@abcdefghi_def.ab/AB</strong></p>
  
  <p>I've also tried this,</p>
  
  <pre><code>@{@"someKey":[NSString stringWithFormat:@"%@@%@\\/AB", someTextField.text, [aDictionary objectForKey:@"someOtherKey"]]};
  </code></pre>
  
  <p>but it won't treat double slash as single slash and someKey value is,</p>
  
  <p><strong>112212234234324@abcdefghi_def.ab\\/AB</strong></p>
  
  <p>NSLog is converting fine.</p>
  
  <p><code>NSLog(@"\\");</code> gives \</p>
  
  <p><code>NSLog(@"\\\\");</code> gives \\</p>
  
  <p><code>NSLog(@"\\/");</code> gives \/</p>
  
  <p>Please help.</p>