iphone Get current year as string

NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"yyyy"];
NSString *yearString = [formatter stringFromDate:[NSDate date]];

// Swift
let dateFormatter = DateFormatter()
dateFormatter.dateFormat = "yyyy"
let year = dateFormatter.string(from: Date())

You can compare NSStrings via the -isEqualToString: method.