NSDataDetector Example:

NSError *error = nil;
NSDataDetector *detector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeLink error:&error];

NSString *stringValue =  @"Two links: useyourloaf.com and apple.com";
NSURL *url = nil;
NSTextCheckingResult *result = [detector firstMatchInString:stringValue
                                                    options:0
                                                      range:NSMakeRange(0, stringValue.length)];
if (result.resultType == NSTextCheckingTypeLink)
{
    url = result.URL;
}
NSLog(@"matched: %@", url);
// matched: http://useyourloaf.com

//--------------------------------------------------------------------

NSString *stringValue = @"Two links: useyourloaf.com and apple.com";   
[detector enumerateMatchesInString:stringValue
                           options:0
                             range:NSMakeRange(0, stringValue.length)
                        usingBlock:^(NSTextCheckingResult *result, NSMatchingFlags flags, BOOL *stop)
{
    if (result.resultType == NSTextCheckingTypeLink)
    {
        NSLog(@"matched: %@",result.URL);
    }        
}];
// matched: http://useyourloaf.com
// matched: http://apple.com


//====================================================================

NSString *string = @"This is a sample of a http://abc.com/efg.php?EFAei687e3EsA sentence with a URL within it.";
NSDataDetector *linkDetector = [NSDataDetector dataDetectorWithTypes:NSTextCheckingTypeLink error:nil];
NSArray *matches = [linkDetector matchesInString:string options:0 range:NSMakeRange(0, [string length])];
for (NSTextCheckingResult *match in matches) {
  if ([match resultType] == NSTextCheckingTypeLink) {
    NSURL *url = [match URL];
    NSLog(@"found URL: %@", url);
  }
}


//====================================================================