How to use Java extends

Understanding inheritance is the key to understanding object-oriented programming. In Java, inheriting an existing class through Keywordextends, the inherited class is called the parent class (superclass, base class), and the new class is called a subclass (derived class). Multiple inheritance is not accepted in Java.
(1) Inheritance

Class Animal{void Eat () {System.out.println ("Animal eat");} void Sleep () {System.out.println ("Animal Sleep");} void Breathe () {System.out.println ("Animal Breathe");}} Class Fish extends Animal{}public class Testnew {public static void main (string[] args) {//TODO auto-generated method Stu Banimal an = new Animal (); FISH fn = new fish (); an.breathe (); Fn.breathe ();}}

Run at Eclipse:
Animal breathe!
Animal breathe!
Each class in the. java file generates a corresponding. class file under the directory bin. The run result shows that the derived class inherits all the methods of the parent class.

(2) Coverage

Class Animal{void Eat () {System.out.println ("Animal eat");} void Sleep () {System.out.println ("Animal Sleep");} void Breathe () {System.out.println ("Animal Breathe");}} Class Fish extends Animal{void breathe () {System.out.println ("Fish Breathe");}} public class Testnew {public static void main (string[] args) {//TODO auto-generated method Stubanimal an = new Animal (); F ISH fn = new Fish (); an.breathe (); Fn.breathe ();}}

Operation Result:

Animal Breathe
Fish Breathe

Defines a method in a subclass that has the same name as the parent class, the return type, and the type of the parameter, called the override of the method. The override of the method occurs between the child class and the parent class. In addition, you can provide access to the parent class with super.

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References: http://zhidao.baidu.com/question/25517733.html

How to use Java extends