How do I URL encode a string

Question

I have a URL string (NSString) with spaces and & characters. How do I url encode the entire string (including the & ampersand

Answer 1

I opted to use the CFURLCreateStringByAddingPercentEscapes call as given by accepted answer, however in newest version of XCode (and IOS), it resulted in an error, so used the following instead:

NSString *apiKeyRaw = @"79b|7Qd.jW=])(fv|M&W0O|3CENnrbNh4}2E|-)J*BCjCMrWy%dSfGs#A6N38Fo~";

NSString *apiKey = (NSString *)CFBridgingRelease(CFURLCreateStringByAddingPercentEscapes(NULL, (CFStringRef)apiKeyRaw, NULL, (CFStringRef)@"!*'();:@&=+$,/?%#[]", kCFStringEncodingUTF8));