day09--抽象类的练习

day09/src/com/inmind/abstract_test07/Demo11.java

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+package com.inmind.abstract_test07;
+/*
+简单练习：定义一个图形类，求周长和面积，但是有不知道如何实现，只能由具体的图形子类(长方形，圆形)实现
+ */
+public class Demo11 {
+    public static void main(String[] args) {
+        //创建一个长方形，求面积和周长
+        Rectangle rectangle = new Rectangle(4, 3);
+        System.out.println("长方形面积为："+rectangle.getArea());
+        System.out.println("长方形周长为："+rectangle.getZC());
+    }
+}

day09/src/com/inmind/abstract_test07/Rectangle.java

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+package com.inmind.abstract_test07;
+//长方形类
+public  class Rectangle extends Shape{
+
+    //在创建长方形对象，必须传入2个属性：长和宽
+    public Rectangle(int chang ,int kuan){
+        super(chang,kuan,0);
+    }
+
+
+    @Override
+    public int getArea() {
+        return getChang()*getKuan();
+    }
+
+    @Override
+    public int getZC() {
+        return 2*(getChang()+getKuan());
+    }
+}

day09/src/com/inmind/abstract_test07/Shape.java

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+package com.inmind.abstract_test07;
+//图形类：定义一些功能和属性
+public abstract class Shape {
+    //至少需要长，宽，半径
+    private int chang;
+    private int kuan;
+    private int r;
+    //定义构造方法
+    public Shape() {
+    }
+
+    public Shape(int chang, int kuan, int r) {
+        this.chang = chang;
+        this.kuan = kuan;
+        this.r = r;
+    }
+
+    //设置get/set方法，访问私有属性
+    public int getChang() {
+        return chang;
+    }
+
+    public void setChang(int chang) {
+        this.chang = chang;
+    }
+
+    public int getKuan() {
+        return kuan;
+    }
+
+    public void setKuan(int kuan) {
+        this.kuan = kuan;
+    }
+
+    public int getR() {
+        return r;
+    }
+
+    public void setR(int r) {
+        this.r = r;
+    }
+
+    //求周长和面积
+    public abstract int getArea();
+    public abstract int getZC();
+}