继承 2—people

19．创建如下三个类：（People类中的三个方法分别输出一些信息，ChinaPeople

和AmericanPeople类重写父类的三个方法）。

package text;

public class People {
     private double height;
     private double weight;
    public double getHeight() {
        return height;
    }
    public void setHeight(double height) {
        this.height = height;
    }
    public double getWeight() {
        return weight;
    }
    public void setWeight(double weight) {
        this.weight = weight;
    }
    //方法
    //打招呼
    public void speakHello()
    {
        System.out.println("Hello!");
    }
    public void averageheight(double highestheight,double minheight)
    {
        height=( highestheight-minheight)/2;
        System.out.println("平均身高为："+height);
    }
    public void averageweight(double highestweight,double lowestweight)
    {
        weight=( highestweight-lowestweight)/2;
        System.out.println("平均身高为："+weight);
    }
    public static void main(String[] args) {
        // TODO 自动生成的方法存根
        People p=new People();
        p.speakHello();
        p.averageheight(190.0,155.0);
        p.averageweight(120.0,90.0);
    }

}

package text;
//extends 继承
//Object 是所有类的父类
public class Chinapeople extends People {
    public void gongFu()
    {
        System.out.println("坐如钟，站如松，睡如弓");
    }
    //重写 覆盖
    public void speakHello()
    {
        System.out.println("你好！");
    }
    public static void main(String[] args) {
        
        Chinapeople cp=new Chinapeople();
        cp.setHeight(100);
        cp.setWeight(50);
        cp.speakHello();
        cp.gongFu();

    }
}

package text;

public class AmericanPeople extends People {
    public void Boxing()
    {
        System.out.println("直拳，勾拳");
    }
    public void SpeakHello()
    {
        System.out.println("Hello");
    }
    public static void main(String[] args) {
        // TODO 自动生成的方法存根
        AmericanPeople ap=new AmericanPeople();
        ap.setHeight(180);
        ap.setWeight(100);
        ap.SpeakHello();
        ap.Boxing();
    }

}