Java —— 类的继承

//class Test import java.util.Scanner; public class Test { public static void main(String[] args){ Scanner scanner = new Scanner(System.in); Vehicle v = new Vehicle(); System.out.println(v.toString()); Car c = new Car(); System.out.println(c.toString()); int speed,whl; String clo; clo = scanner.next(); speed = scanner.nextInt(); whl = scanner.nextInt(); c.setColor(clo); c.setSpeed(speed); c.setNbWheels(whl); System.out.println(c.toString()); /* * * isMove()函数是Car类的父类所拥有的方法成员。 * Car类通过对Vehicle类的继承，可以直接通过Car类的对象引用来对isMove()方法调用。 * */ if(c.isMove()){ System.out.println("This car is moving"); } else System.out.println("This car is not moving"); //该for循环是为了验证decelerate()和isMove()的方法的 for(int i = 0; i<10; i++) c.decelerate(); if(c.isMove()){ System.out.println("This car is moving"); } else System.out.println("This car is not moving"); } } //class Car //Accelerate: speed = speed + 1; //Decelerare: speed = speed - 1; public class Car extends Vehicle { private int nbWheels; public Car(){ System.out.println("I am a car"); } public String toString(){ return "I am a " + super.getColor() + " car,speed: "+ super.getSpeed() +". And my nbWheels are "+nbWheels; } public int getNbWheels() { return nbWheels; } public void setNbWheels(int nbWheels) { this.nbWheels = nbWheels; } } //class Vehicle public class Vehicle { private int speed; private String color; public Vehicle(){ System.out.println("I am a Vehicle"); speed = 0; color = "blue"; } public void accelerate(){ speed ++; } public void decelerate(){ if(getSpeed() >= 1) speed --; } public boolean isMove(){ if(getSpeed() > 0) return true; return false; } public String toString(){ return "I am a "+color+" vehicle and my current speed is " + speed; } public int getSpeed() { return speed; } public void setSpeed(int speed) { this.speed = speed; } public String getColor() { return color; } public void setColor(String color) { this.color = color; } }