Some general remarks on Java - An Introduction to Graphical User Interfaces with Java Swing - page 298

Three classes are defined, AClass , BClass and CClass . AClass has (non-static)
method methodA1 . Now BClass wants to use that method. CClass is the 'master'
class which uses both AClass and BClass . The structure is listed below.

1. class AClass{
2.
3.

public AClass(){

4.

}

5.
6.

public int methodA1(){

7.

// commands

8.

}

9. }
10.
11. -----------------------------------
12.
13. class BClass{
14.
15.

public BClass(){

16. }

17.
18. public void methodB1(){

19. int n=methodA1();

20. // methodA1 unknown

21.

}

22.
23.
24. }
25.
26.
27. -----------------------------------
28.
29. class CClass{
30.
31.

public CClass(){

32.

}

33.
34.

public static void main(String[] a){

35. AClass a = new AClass();

36. BClass b = new BClass();

37. }

38.
39. }

This will result in a compile-time error at the line

int n=methodA1();