Learn Java for Web Development

390 APPENDIX A: Introduction to Java

Listing A-15 illustrates how Figure A-1 could be implemented in code. It illustrates implementation
inheritance using the keyword extends in line 26.

Listing A-15. Implementation Inheritance

1. package apress.appendix_A


2. 
   


3. public class ClassA {


4. 
   


5. // Instance methods


6. public void method1() {


7. System.out.println(" classA - method1");


8. 
   


9. }


10. 
    


11. private void method2() {


12. System.out.println(" classA - method2");


13. 
    


14. }


15. 
    


16. // Static methods


17. public static void method3() {


18. System.out.println(" classA - method3");


19. 
    


20. }


21. 
    


22. }

Figure A-1. Parent-child relationship. ClassB extends ClassA