Simple Inheritance Example: Java

Generic class to inherit the circles and rectangles.

Package circle;public class geometric {private string color= "White";p rivate  boolean filled;private java.util.date datecreated;public geometric () {dateCreated=new  java.util.date ();} Public geometric (string color,boolean filled) {datecreated=new java.util.date (); this.filled =filled;this.color=color;} Public java.util.date getdatecreated () {return datecreated;} Public string getcolor () {return color;} Public void setcolor (String color) {this.color=color;} Public boolean isfilled () {return filled;} Public void setfilled (boolean filled) {this.filled=filled;} Public string tostring () {return  "Created on" +datecreated+ "\ncolor:" +color+ "and filled   "+filled;}} package circle;import java.util.*;p Ublic class circle extends geometric{private  double radius;public circle () {}PUBLIC CIRCLE (Double radius) {This.radius=radius;} Public circle (double radius,string color,boolean filled) {This.radius=radius;setcolor (color ); setfilled (filled);} Public double getradius () {Return radius;} Public void setradius (Double radius) {This.radius=radius;} Public double getarea () {Return math.pi*radius*radius;}} Package circle;public class rectangle extends geometric {private double  width;private double height;public rectangle () {}public rectangle (Double width, Double height) {this.width=width;this.height=height;} Public rectangle (double width,double height,string color,boolean filled) {this.width= Width;this.height=height;setcolor (color); setfilled (filled);} Public double getwidth () {return width;} Public void setwidth (double width) {this.width=width;} Public double getheight () {return height;} Public&nbsP;void setheight (double height) {this.height=height;} Public double getarea () {return width*height;} Public double getperimeter () {return 2* (width+height);}} Package circle;public class main {public static void main (String[]  args)  {/**geometric g1=new geometric (); g1.setfilled (true); Geometric g2=new geometric ("Black", false); System.out.print (G1.tostring ()); System.out.print (G2.tostring ()); */circle c1=new circle (); C1.setradius (1.0); System.out.println (C1.getarea ()); Circle c2=new circle (2.0, "Red", true); System.out.println (C2.getarea ()); Rectangle r1=new rectangle (); System.out.println (R1.getarea ()); Rectangle r2=new rectangle (1.0,2.0); System.out.println (R2.getarea ());}}

When there are two packages in Java, if you use other packages in a package class, you can import the. Package name. class name; easy to use.

Overloading means that you can define multiple methods with the same name, but these methods have different signatures.

The overriding method means providing a completely new implementation for the methods in the subclass. Specific examples are as follows:

Method P of Class A overrides the same method defined in class B. public class Test{public static void Main (string[] args) {a a=new a (); A.P () A.P (10.0);}} Class B{public void P (double i) {System.out.println (i*2);}} Class A extends B{public void P (double i) {System.out.println (i);}}

Class B has two overloaded methods P (double i) and P (int i), and the P (double i) Method of Class B is inherited. public class Test{public static void Main (string[] args) {a a=new a (); A.P () A.P (10.0);}} Class B{public void P (double i) {System.out.println (i*2);}} Class A extends b{public void p (int i) {System.out.println (i);}}

This article is from the "Small Stop" blog, please be sure to keep this source http://10541556.blog.51cto.com/10531556/1880621

Simple Inheritance Example: Java