【java】简单继承练习

1.

package 上机3;

public class test {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
        Bird bird=new Bird("公");
        bird.shout();
        Dog dog=new Dog("萨摩");
        dog.shout();
        Person p=new Person("张三");
        p.speak();
        Student stu=new Student("李四","1234567");
        stu.study();
	}

}

class Animal
{
	protected String zhonglei; //动物种类
	public void shout()
	{
		System.out.println("动物发出叫声");
	}
}

class Bird extends Animal
{
	private String sex; //鸟的性别
	public Bird(String sex)
	{
		super.zhonglei="哺乳类";
		this.sex=sex;
	}
	public void shout()
	{
		System.out.println("吱吱");
	}
}

class Dog extends Animal
{
	private String pinzhong;  //狗的品种
	public Dog(String pinzhong)
	{
		super.zhonglei="哺乳类";
		this.pinzhong=pinzhong;
	}
	public void shout()
	{
		System.out.println("汪汪");
	}
}

class Person extends Animal
{
	protected String name;
	public Person(String name)
	{
		super.zhonglei="哺乳类";
		this.name=name;
	}
	public void speak()
	{
		System.out.println(name+"交流");
	}
}

class Student extends Person
{
	private  String num;  //学号 
	public Student(String name,String num)
	{
		super(name);   //调用父类Person的构造函数
		this.num=num;
	}
	public void study()
	{
		System.out.println(super.name+"学习");
	}
}

2. 建立一个汽车Auto类，包括轮胎个数，汽车颜色，车身重量、速度等成员变量。并通过不同的构造方法创建实例。至少要求：汽车能够加速，减速，停车。再定义一个小汽车类Car，继承Auto，并添加空调、CD等成员变量，覆盖加速，减速的方法

package 上机3;

public class test1 {
    public static void main(String[] args)
    {
    	Auto a=new Auto(8,"蓝色",100);
    	a.setSpeed(30);
    	a.addSpeed(20);
    	a.subSpeed(10);
    	Car c=new Car(4,"白色",80,"空调","张杰专辑");
    	c.addSpeed(30);
    	c.subSpeed(10);
    }
}

class Auto
{
	protected int tyreNum; //轮胎个数
	protected String collor; //汽车颜色
	protected int weight;//车身重量
	protected int speed; //速度
	
	public Auto(int tyreNum,String collor,int weight)
	{
		this.tyreNum=tyreNum;
		this.collor=collor;
		this.weight=weight;
	}
	
	public void setSpeed(int speed)
	{
		this.speed=speed;
	}
	
	public void addSpeed(int num)
	{
		int maxSpeed=120;
	    int ret=speed+num;
	    if(ret<=maxSpeed)
		{
	    	speed=ret;
		    System.out.println("当前车速"+speed);
		}
	    else
	    {
	    	speed=maxSpeed;
	    	System.out.println("车速已达上限，无法继续加速");
	    }
	}
	
	public void subSpeed(int num)
	{
		int ret=speed-num;
		if(ret>0)
		{
			speed=ret;
			System.out.println("当前车速"+speed);
		}
		else
		{
			speed=0;
			System.out.println("车速为0，无法继续减速");
		}
	}
	
	public void stop()
	{
		speed=0;
		System.out.println("车停");
	}
}

class Car extends Auto
{

    public Car(int tyreNum,String collor,int weight,String kongtiao,String CD)
    {
    	super(tyreNum,collor,weight);
    	this.kongtiao=kongtiao;
    	this.CD=CD;
    }
    
    public void addSpeed(int num)
    {
    	super.speed=num;
    	if(num<=130)
    	System.out.println("小车速度已加至"+num);
    	else
    		System.out.println("超速");
    }
    
    public void subSpeed(int num)
    {
    	super.speed=num;
    	if(num>=0)
    		System.out.println("小车速度以减至"+num);
    	else
    		System.out.println("小车速度不能为负值");
    }
	protected String kongtiao;
	protected String CD;
}