How to Concatenate a string in URL on Xcode (Objective-c)?

I need to replace "CurrentLocation" with a value in following URL. "CurrentLocation" is a predefined string and it gives a dynamic value (I mean different name of location/city each time). I need help, How to do it in Objective-C ??

NSURL *MainURL = [NSURL URLWithString:@"http://news.googl开发者_Go百科e.com/news?q=location:CurrentLocation&output=rss"];

In JavaScript i would do something like this;

var a="Google"; var b=".com"; var c=".np"; var d=a+b+c; document.write(d);

Please somebody help me with this. Thanks!!

You can use the the stringWithFormat static message on the NSString class. This will create an autoreleased NSString object using the formatting you specify (using printf style format string). So for your case:

// get the current location from somewhere
NSString * yourCurrentLocation = @"Sydney";

// create your urlString %@ is replaced with the yourCurrentLocation argument
NSString * urlString = [NSString stringWithFormat:@"http://news.google.com/news?q=location:%@&output=rss", yourCurrentLocation];

also, a good method is stringByAppendingString, here is more info in the apple site.

NSString *errorTag = @"Error: ";
NSString *errorString = @"premature end of file.";
NSString *errorMessage = [errorTag stringByAppendingString:errorString];