Introduction

Please go through my first article on Single Level Inheritance in Java:
How to use Single Inheritance in Java
In this article, we learn about multilevel inheritance using Notepad. A class can be derived from a derived class and that is known as multilevel inheritance.

Step 1
Let's open Notepad and write the following code:
  1. class A
  2. {
  3. void disp()
  4. {
  5. System.out.println("disp method");
  6. }
  7. }
  8. class Test extends A
  9. {
  10. void show()
  11. {
  12. System.out.println("show method");
  13. }
  14. }
  15. class demo extends Test
  16. {
  17. public static void main(String arg[])
  18. {
  19. demo d=new demo();
  20. d.show();
  21. d.disp();
  22. }
  23. }
Step 2
In this program we use "extends" to inherit all the properties from the base class or the parent's class.
Step 3
Name it "multy.java" and save the file in any location. I saved mine at "c:/kiran/program".
Step 4
Open a command prompt (press Windows + R and write cmd and hit OK).
Step 5
Go to "c:/app" using the command prompt.
Step 6
Set the path (path set means where you save your Java file).
Step 7
Now write the following code for checking whether or not the Java file has compiled.
  1. javac swap.java
My Java program compiled successfully.
Step 8
Write the following code in the command prompt. Press Enter and see the output.
  1. java demo
  2. // demo is a class name which is written in my "swap.java" file.
Output
Happy coding.