Android How to Program, 3/e

D.5 Notes on Declaring and Using Methods

There are three ways to call a method:

1. Using a method name by itself to call another method of the same class—such as maximum(number1, number2, number3) in line 21 of Fig. D.2.

2. Using a variable that contains a reference to an object, followed by a dot (.) and the method name to call a non-static method of the referenced object—such as the method call in line 13 of Fig. C.3, myGradeBook.displayMessage(), which calls a method of class GradeBook from the main method of GradeBookTest.

3. Using the class name and a dot (.) to call a static method of a class—such as Math.sqrt(900.0) in Section D.3.

A static method can call only other static methods of the same class directly (i.e., using the method name by itself) ...