Shortcuts in Objective-C to concatenate NSStrings

I keep returning to this post and always end up sorting through the answers to find this simple solution that works with as many variables as needed:

[NSString stringWithFormat:@"%@/%@/%@", three, two, one];

For example:

NSString *urlForHttpGet = [NSString stringWithFormat:@"http://example.com/login/username/%@/userid/%i", userName, userId];

If you have 2 NSString literals, you can also just do this:

NSString *joinedFromLiterals = @"ONE " @"MILLION " @"YEARS " @"DUNGEON!!!";

That's also useful for joining #defines:

#define STRINGA @"Also, I don't know "
#define STRINGB @"where food comes from."
#define JOINED STRINGA STRINGB

Enjoy.

Two answers I can think of... neither is particularly as pleasant as just having a concatenation operator.

First, use an NSMutableString, which has an appendString method, removing some of the need for extra temp strings.

Second, use an NSArray to concatenate via the componentsJoinedByString method.

An option:

[NSString stringWithFormat:@"%@/%@/%@", one, two, three];

Another option:

I'm guessing you're not happy with multiple appends (a+b+c+d), in which case you could do:

NSLog(@"%@", [Util append:one, @" ", two, nil]); // "one two"
NSLog(@"%@", [Util append:three, @"/", two, @"/", one, nil]); // three/two/one

using something like

+ (NSString *) append:(id) first, ...
{
    NSString * result = @"";
    id eachArg;
    va_list alist;
    if(first)
    {
        result = [result stringByAppendingString:first];
        va_start(alist, first);
        while (eachArg = va_arg(alist, id)) 
        result = [result stringByAppendingString:eachArg];
        va_end(alist);
    }
    return result;
}