好久没有敲代码了 变得生疏和脑子不够用了 用慕课来重温下知识点还是很好的 这是我在看了老师解题所给出的部分代码后自己补上的 每个类都用横线分隔开了 主要由5个类组成 一个父类Car 三个子类Truck、PickUp、PassengerCar 和一个主函数类Main组成 本人写的代码很烂 写在这里只是给更多幕友一个参考的地方 也说不上参考就是给大家随便看下 

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package com.demo_h;

public class Car {

protected String name;

protected double rent;

public String getName() {

return name;

}

public void setName(String name) {

this.name = name;

}

public double getRent() {

return rent;

}

public void setRent(double rent) {

this.rent = rent;

}

}

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package com.demo_h;

public class Truck extends Car {

private double cargoCapacity;

public Truck(String name,double rent,double cargoCapacity)

{

this.name = name;

this.rent = rent;

this.setCargoCapacity(cargoCapacity);

}

public void setCargoCapacity(double cargoCapacity) {

this.cargoCapacity = cargoCapacity;

}

public double getCargoCapacity() {

return cargoCapacity;

}

}

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package com.demo_h;

public class PickUp extends Car {

private double peopleCapacity;

private double cargoCapacity;

public PickUp(String name,double rent,double peopleCapacity,double cargoCapacity)

{

this.name = name;

this.rent = rent;

this.setPeopleCapacity(peopleCapacity);

this.setCargoCapacity(cargoCapacity);

}

public void setCargoCapacity(double cargoCapacity) {

this.cargoCapacity = cargoCapacity;

}

public double getCargoCapacity() {

return cargoCapacity;

}

public void setPeopleCapacity(double peopleCapacity) {

this.peopleCapacity = peopleCapacity;

}

public double getPeopleCapacity() {

return peopleCapacity;

}

}

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package com.demo_h;

public class PassengerCar extends Car {

private double peopleCapacity;

public PassengerCar(String name,double rent,double peopleCapacity)

{

this.name = name;

this.rent = rent;

this.peopleCapacity = peopleCapacity;

}

public double getPeopleCapacity() {

return peopleCapacity;

}

public void setPeopleCapacity(double peopleCapacity) {

this.peopleCapacity = peopleCapacity;

}

}

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package com.demo_h;

import java.util.Scanner;

public class Main {

/*

* @param args

*/

public static void main(String[] args) {

// TODO Auto-generated method stub

//用父类数组指向子类实例化对象，并且用构造方法赋值

Car[] carsForRent = {new PassengerCar("奥迪", 500, 4),new PassengerCar("马自达", 400, 4),

new PassengerCar("金龙", 800, 20),new PickUp("皮卡雪", 450, 4, 2),

new Truck("松花江", 400, 4),new Truck("依维柯", 1000, 20)};

System.out.println("****欢迎来到答答租车系统****");

System.out.println("你是否要租车：1是  0否");

Scanner scan = new Scanner(System.in);

String input = scan.next();

if(input.equals("1"))

{

System.out.println("你可租车的类型及其价目表：");

System.out.println("序号\t汽车名称\t租金\t容量");

int i = 1;

//显示所有的车型

for(Car currentCar:carsForRent)//foreach循环显示数组内容

{

if(currentCar instanceof PassengerCar)//判断是否指向当前子类对象，然后进行向下转型

{

System.out.println(i+"\t"+currentCar.getName()+"\t"+currentCar.getRent()

+"元/天\t载人"+(int)((PassengerCar) currentCar).getPeopleCapacity()+"人");

i++;

}

if(currentCar instanceof Truck)

{

System.out.println(i+"\t"+currentCar.getName()+"\t"+currentCar.getRent()

+"元/天\t载货"+((Truck) currentCar).getCargoCapacity()+"吨");

i++;

}

if(currentCar instanceof PickUp)

{

System.out.println(i+"\t"+currentCar.getName()+"\t"+currentCar.getRent()

+"元/天\t载人"+(int)((PickUp) currentCar).getPeopleCapacity()+"人.载货"+

((PickUp) currentCar).getCargoCapacity()+"吨");

i++;

}

}

System.out.println("请输入您要汽车的数量");

int carNum = scan.nextInt();

int accout = 0;

int peopleNum = 0;

int cargoNum = 0;

Car[] carsForRent01 = new Car[carNum]; //此数组方便为打印车辆名字而建

if(carNum>0&&carNum<7)//限制汽车数量

{

for(int a=0;a<carNum;a++)

{

System.out.println("请输入第"+(a+1)+"辆车的序号");

int num = scan.nextInt();

switch (num) { //用switch语句实现选择以及对金额、载客量和数组的赋值

case 1:

accout = accout+500;

peopleNum = peopleNum+4;

carsForRent01[a] = carsForRent[0];

break;

case 2:

accout = accout+400;

peopleNum = peopleNum+4;

carsForRent01[a] = carsForRent[1];

break;

case 3:

accout = accout+450;

peopleNum = peopleNum+4;

cargoNum = cargoNum+2;

carsForRent01[a] = carsForRent[2];

break;

case 4:

accout = accout+800;

peopleNum = peopleNum+20;

carsForRent01[a] = carsForRent[3];

break;

case 5:

accout = accout+400;

cargoNum = cargoNum+4;

carsForRent01[a] = carsForRent[4];

break;

case 6:

accout = accout+1000;

cargoNum = cargoNum+20;

carsForRent01[a] = carsForRent[5];

break;

default:

System.err.println("输入车辆序号不符合标准！");

break;

}

}

}

else

{

System.out.println("输入汽车数量过大或则不符合标准！");

}

System.out.println("*****你的账单*****");

System.out.println("---可载客的车有---");

for(Car currentCar:carsForRent01) //输出可载客车的名字 注意进行对象比较

{

if(currentCar instanceof PassengerCar)

{

System.out.print(currentCar.getName()+"  ");

}

}

System.out.println("共载人："+peopleNum+"人");

System.out.println("---可载货的车有---");

for(Car currentCar:carsForRent01)

{

if((currentCar instanceof Truck)||(currentCar instanceof PickUp))

{

System.out.print(currentCar.getName()+"  ");

}

}

System.out.println("共载货："+cargoNum+"吨");

System.out.println("租车总价格："+accout+"￥");

}

else

{

System.out.println("退出系统 欢饮下次光临！");

System.exit(-1);

}

}

}