objective c - Receive Data from javascript -

I have a stupid question ... sometimes I see the developers using the following code ...

  NSString * newURL = [_parameters objectForKey: @ "url"];  

When I use it, I get an error ... What are the permratirs here and how to declare it ??

I can provide more examples.

  NSLog (@ "Savings IMA's Collapse"); // To change the baseline to UIIds NSDLL * URL = // Google Code [ns URL URL YouthString: [self. _premites objectfree: @ "image data"]]; NSData * imageData = [NSData dataWithContentsOfURL: URL]; UIImage * img = [UIImage imageWithData: imageData]; / * If (IMG! = Zero) {UIImageWriteToSavedPhotosAlbum (IMG, self, zero, zero); } * /  

_parameters looks like code first Defined with, e.g.

  NSDictionary _parameters = [NSDictionary dictionaryWithObjects: @ "foo", @ "bar", for nail zero: @ "url", @ "host", zero];  

What exactly is your question? How is it related to javascript (editing: the question was marked as javascript)? Did you know that the language you use is aimed ?