Programming in Objective-C, Sixth Edition

Multiple Arguments to Methods

Let’s continue to work with the Fraction class and make some additions. You have defined six methods. It would be nice to have a method to set both the numerator and the denominator with a single message. You define methods that take multiple arguments simply by listing each successive argument followed by a colon. This becomes part of the method name. For example, the method named addEntryWithName:andEmail: takes two arguments, presumably a name and an email address. The method addEntryWithName:andEmail:andPhone: takes three arguments: a name, an email address, and a phone number.

A method to set both the numerator and the denominator could be named setNumerator:andDenominator:, and you might use it like this: ...