Optional arguments in Objective-C 2.0?

You can declare multiple methods:

- (void)print;
- (void)printWithParameter:(id)parameter;
- (void)printWithParameter:(id)parameter andColor:(NSColor *)color;

In the implementation you can do this:

- (void)print {
    [self printWithParameter:nil];
}

- (void)printWithParameter:(id)parameter {
    [self printWithParameter:nil andColor:[NSColor blackColor]];
}

Edit:

Please do not use print and print: at the same time. First of all, it doesn’t indicate what the parameter is and secondly no one (ab)uses Objective-C this way. Most frameworks have very clear method names, this is one thing that makes Objective-C so pain-free to program with. A normal developer doesn’t expect this kind of methods.

There are better names, for example:

- (void)printUsingBold:(BOOL)bold;
- (void)printHavingAllThatCoolStuffTurnedOn:(BOOL)coolStuff;