作业:实现一个类,用来表示图形,定义方法,可以分别计算出矩形和圆形的面积和周长(要求用到抽象思维)
思路,这个作业说要用到抽象思维,所以肯定要抽象出一些公共的东西,这里的矩形和圆形 能抽象出公共的面积和周长方法,
我们可以用接口来实现;
package com.xuyigang1234.chp03.lianxi; /** * 图形接口 * */ public interface XingZhuang { public void mianJi(); public void zhouChang(); }
package com.xuyigang1234.chp03.lianxi; /** * 矩形类 * */ public class Rectangle implements XingZhuang{ private float a; private float b; public Rectangle(float a,float b) { super(); this.a=a; this.b=b; } @Override public void mianJi() { System.out.println("矩形的面积为:"+ this.a*this.b); } @Override public void zhouChang() { System.out.println("矩形的周长为:"+ (this.a+this.b)*2); } }
package com.xuyigang1234.chp03.lianxi; /** * 圆形类 * */ public class Circular implements XingZhuang{ private float r; public Circular(float r) { super(); this.r=r; } @Override public void mianJi() { System.out.println("圆形的面积为:"+ Math.PI*this.r*this.r); } @Override public void zhouChang() { System.out.println("圆形的周长为:"+ Math.PI*this.r*2); } }
package com.xuyigang1234.chp03.lianxi; public class TestXingZhuang { public static void main(String[] args) { XingZhuang jx= new Rectangle(3,3); jx.mianJi(); jx.zhouChang(); XingZhuang yx= new Circular(3); yx.mianJi(); yx.zhouChang(); } }