就算先这样吧，路过的大佬帮忙看看有没有优化的地方_(:з」∠)_

Car.clas                        //父类、抽象类

package cars;

public abstract class Car {

       protected double price; //定义价格

        protected String carname; //定义名称

        public abstract String work();

}

MannedCar.class       //载人车子类

package cars;

public class MannedCar extends Car {

     private int people; //定义乘坐人数

    public int getPeople() {

           return people;

    }

     public void setPeople(int people) {

           this.people = people;

     }

     public MannedCar(String carname, double price, int people) {

         this.people = people;

         this.price = price;

         this.carname = carname;

     }

     @Override

     public String work() {

         // TODO 自动生成的方法存根

         return carname + "\t\t" + price + "/天" + "\t\t" + "载人:" + people + "人";

     }

}

  CarryCar.class        //货车子类

package cars;

public class CarryCar extends Car {

     private double weight; //定义载重量

         public double getWeight() {

         return weight;

     }

     public void setWeight(double weight) {

         this.weight = weight;

     }

     public CarryCar( String carname, double price, double weight) {

         this.weight = weight;

         this.price = price;

         this.carname = carname;

     }

     @Override

     public String work() {

         // TODO 自动生成的方法存根

         return carname + "\t\t" + price + "/天" + "\t\t" + "载货:" + weight + "吨";

     }

}

DualCar.class        //载人/货车 子类    

package cars;

public class DualCar extends Car {

     private int people; //定义乘坐人数

     private double weight; //定义载重量

     public int getPeople() {

         return people;

     }

     public void setPeople(int people) {

         this.people = people;

     }

     public double getWeight() {

         return weight;

     }

     public void setWeight(double wewight) {

         this.weight = wewight;

     }

     public DualCar( String carname, double price, int people, double weight) {

         this.people = people;

         this.weight = weight;

         this.price = price;

         this.carname = carname;

     }

     @Override

     public String work() {

         // TODO 自动生成的方法存根

         return carname + "\t\t" + price + "/天" + "\t\t" + "载货:" + weight + "吨" + "\t\t" + "载人:" + people + "人";

     }

}

BuyCar.class         //调试

package cars;

import java.util.Scanner;

public class BuyCar {

     public static void main(String[] args) {

         Car[] cars = {

             new MannedCar("奥德A4", 500, 6),

             new MannedCar("大黄蜂", 950, 4),

             new CarryCar("马自达", 400, 1.2),

             new CarryCar("金龙", 450, 1.6),

             new DualCar("松花江", 400, 2, 1.6),

             new DualCar("伊维特", 510, 4, 2.4),

         };

         Scanner scan = new Scanner(System.in);

         System.out.println("请选择你的服务： 0（退出）, 1 （租车服务）");

         int choice = scan.nextInt();

         if (choice == 1) {

             System.out.println("**************可租用汽车表**************");

             for (int i = 0; i < cars.length; i++) {

                  System.out.println("序号： " + i + "\t" + cars[i].work());

         }

         System.out.print("请输入你要购买的数量: ");

         int num = scan.nextInt();

         // 判断购买数量是否非法

         if (num <= 0) {

             System.out.println("错误!");

             System.exit(0);

         }else{

             int[] chose_cars = new int[num]; //存储选择的车辆序号数组

             double allprice = 0; //存储总价钱

             for (int i = 0; i < num; i++) {

             System.out.print("请输入你要购买车辆的序号： ");

             int chose_car = scan.nextInt();

             if (chose_car < 0 || chose_car >= cars.length) {

             i--;

             System.out.println("不存在此车辆");

             continue;

         }else{

             chose_cars[i] = chose_car;

         }

     }

     System.out.print("请输入租借天数: ");

     int day = scan.nextInt();

     System.out.println("**************您选择的车辆列表**************");

     for(int chose_car: chose_cars){

     allprice += cars[chose_car].price * day; //计算总价钱

     System.out.println("序号： " + chose_car + "\t" +cars[chose_car].work());

     }

     System.out.println("您总共需要支付: " + allprice);

     }

     }else {

         System.out.println("您已退出服务！");

         System.exit(0);

     }

     scan.close();

     }

}

附运行结果