Java繼承練習題

第一題

建立一個汽車Auto類，包括輪胎個數，汽車顏色，車身重量、速度等成員變量。並通過不同的構造方法創建實例。至少要求：  汽車能夠加速，減速，停車。 再定義一個小汽車類Car，繼承Auto，並添加空調、CD等成員變量，覆蓋加速，減速的方法

 

 

 

第二題

寫一個Person類，有編號id,姓名name,職位job。

構造方法帶三個參數。

方法：

登陸login

注冊register

自我介紹talk

 

寫一個學生Student類繼承Person類，方法有：考試test

屬性有：學費money

 

寫一個老師Teacher類繼承Person類，

屬性有 工資salary

方法有：工作work

寫一個測試類TestPerson，測試學生和老師

學生：姓名-張三  職位-學生  學費-18000

老師：姓名-李四  職位-老師  工資-8000

 

注冊、登陸輸出就可以，自我介紹輸出屬性​

 

第三題

定義一個父類:形狀類Shapes，里面有兩個方法，分別是求面積和周長。

定義一個子類：矩形Rectangle

定義一個子類：三角形 Triagle

定義一個子類：圓 Circle

定義一個測試類：傳入圓的半徑4 輸出周長和面積

                傳入矩形的長和寬4，5 輸出周長和面積

                傳入三角形三邊：3，4，5 輸出周長和面積

 

 

第一題：
package homework;

public class Auto {
    protected int gears;
    protected String color;
    protected double weight;
    protected double speed;
    
    public Auto() {
        this.gears=4;
        this.color="黃色";
        this.weight=200;
        this.speed=50;
    }

    public Auto(int gears, String color, double weight, double speed) {
        super();
        this.gears = gears;
        this.color = color;
        this.weight = weight;
        this.speed = speed;
    }
    public void speedUp()
    {
        speed+=5;
        System.out.println("加速至"+speed);
    }
    public void speedDown()
    {
        speed-=5;
        System.out.println("減速至"+speed);
    }
    public void stop()
    {
        speed=0;
        System.out.println("汽車停止，速度是"+speed);
    }
    
}

package homework;

public class Car extends Auto{
    protected String kongtiao;
    protected String CD;
    
    public Car() {
        super();
        kongtiao="品牌1空調";
        CD="CD1";
    }
    
    public Car(int gears, String color, double weight, double speed,String kongtiao, String cD) {
        super(gears, color, weight, speed);
        this.kongtiao = kongtiao;
        CD = cD;
    }
    
    @Override
    public void speedUp(){
        super.speed+=10;
        System.out.println("加速至"+speed);
    }
    @Override
    public void speedDown() {
        speed-=10;
        System.out.println("減速至"+speed);
    }
    
    public void information()
    {
        System.out.println("當前是"+color+"的"+gears+"輪"+color+"的重"+weight+"的配有"+kongtiao+"和"+CD+"的車子，當前時速為"+speed);
    }
    
}
package homework;

public class TestAuto {
    public static void main(String[] args) {
        Car car=new Car();
        car.information();
        car.speedDown();
        car.speedUp();
        car.stop();
        System.out.println();
        Car car2=new Car(3, "白色", 300, 70,"品牌2空調", "CD2");
        car2.information();
        car2.speedDown();
        car2.speedUp();
        car.stop();
    }
}



第二題：
package homework;

public class Person {
    protected int id;
    protected String name;
    protected String job;
    
    public Person(int id, String name, String job) {
        this.id = id;
        this.name = name;
        this.job = job;
    }
    public void login()
    {
        System.out.println("登陸成功");
    }
    public void register()
    {
        System.out.println("注冊成功");
    }
    public void talk()
    {
        System.out.println("大家好！我是"+name+",編號是"+id+",職位是"+job);
    }
}

package homework;

public class Student extends Person {
    protected double money;
    
    public Student(int id, String name, String job, double money) {
        super(id, name, job);
        this.money = money;
    }

    public void test()
    {
        System.out.println("我在考試");
    }
    public void information()
    {
        System.out.println("姓名-"+name+"\t職位-"+job+"\t學費"+money);
    }
    
}

package homework;

public class Teacher extends Person{
    protected double salary;
    
    public Teacher(int id, String name, String job, double salary) {
        super(id, name, job);
        this.salary = salary;
    }

    public void work()
    {
        System.out.println("我在工作");
    }
    public void information()
    {
        System.out.println("姓名-"+name+"\t職位-"+job+"\t工資"+salary);
    }
}
package homework;

public class TestPerson {

    public static void main(String[] args) {
        Student stu=new Student(1, "張三", "學生", 18000);
        stu.login();
        stu.register();
        stu.talk();
        stu.test();
        stu.information();
        System.out.println();
        Teacher tea=new Teacher(2, "張老師", "老師", 8000);
        tea.login();
        tea.register();
        tea.talk();
        tea.information();
    }

}



第三題：
package homework;

public class Shapes {
    public void area()
    {
        System.out.println("求面積");
    }
    public void zhouChang()
    {
        System.out.println("求周長");
    }
}
package homework;

public class Rectangle extends Shapes {
    private int chang;
    private int kuan;
    
    public Rectangle(int chang, int kuan) {
        super();
        this.chang = chang;
        this.kuan = kuan;
    }
    @Override
    public void area() {
        System.out.println("長方形面積是"+chang*kuan);
    }
    @Override
    public void zhouChang() {
        System.out.println("長方形周長是"+(chang+kuan)*2);
    }
    
}
package homework;

public class Circle extends Shapes{
    private int a;

    public Circle(int a) {
        super();
        this.a = a;
    }
    @Override
    public void area() {
        System.out.println("圓形面積是"+a*a*Math.PI);
    }
    @Override
    public void zhouChang() {
        System.out.println("圓形周長是"+a*Math.PI*2);
    }
    
    
    
}
package homework;

public class Triagle extends Shapes {
    private int a;
    private int b;
    private int c;

    
    public Triagle(int a, int b, int c) {
        super();
        this.a = a;
        this.b = b;
        this.c = c;
    }
    public void area() {
        System.out.println("三角形面積是"+Math.sqrt((a+b+c)*(a+b-c)*(a+c-b)*(b+c-a))/4);
    }
    @Override
    public void zhouChang() {
        System.out.println("三角形周長是"+(a+b+c));
    }
}
package homework;

public class TestShapes {

    public static void main(String[] args) {
        Circle circle=new Circle(1);
        circle.area();
        circle.zhouChang();
        Rectangle rectangle=new Rectangle(2, 3);
        rectangle.area();
        rectangle.zhouChang();
        Triagle triagle=new Triagle(3, 4, 5);
        triagle.area();
        triagle.zhouChang();
    }

}