定义父类和子类

package com.dada;
public class ToastCar {
    private String carStyle;//车型
    private int money;//租金(元/天）
    private int weight;//载货量
    private int people;//载人量
    public String getCarStyle() {
        return carStyle;
    }
    public void setCarStyle(String carStyle) {
        this.carStyle = carStyle;
    }
    public int getMoney() {
        return money;
    }
    public void setMoney(int money) {
        this.money = money;
    }
    public int getWeight() {
        return weight;
    }
    public void setWeight(int weight) {
        this.weight = weight;
    }
    public int getPeople() {
        return people;
    }
    public void setPeople(int people) {
        this.people = people;
    }

    }

package com.dada;

public class PeopleCar extends ToastCar {
    public PeopleCar(String carStyle,int money,int weight,int people){
        this.setCarStyle(carStyle);
        this.setMoney(money);
        this.setWeight(weight);
        this.setPeople(people);
    }
}

package com.dada;

public class TruckCar extends ToastCar {
    public TruckCar(String carStyle,int money,int weight,int people){
        this.setCarStyle(carStyle);
        this.setMoney(money);
        this.setWeight(weight);
        this.setPeople(people);
}

}

package com.dada;

public class PickUp extends ToastCar {
    public PickUp(String carStyle,int money,int weight,int people){
        this.setCarStyle(carStyle);
        this.setMoney(money);
        this.setWeight(weight);
        this.setPeople(people);
    }
}

主程序

package com.dada;

import java.util.Scanner;

public class Initial {
    public static void main(String[] args){
        PeopleCar[] pc = {new PeopleCar("奥迪A4",500,0,4),new PeopleCar("马自达6",400,0,4),
                new PeopleCar("金龙",500,0,20)};
        TruckCar[] tc={new TruckCar("松花江",400,4,0),new TruckCar("依维柯",1000,20,0)};
        PickUp[] pu={new PickUp("皮卡雪6",450,2,4)};//输入车辆数据
        int totalPeople=0;//定义总载人数
        int totalWeight=0;//定义总载重量
        int totalMoney=0;//定义总单价
        String[] style=new String[(pc.length+tc.length+pu.length)];//定义字符串数组用来存放选取的车的车型

        Scanner se = new Scanner(System.in);//键盘输入

        int a=0;
        System.out.println("欢迎使用答答租车系统"+"\n"+"请选择是否想租车：1、是  2.否");
        int i=se.nextInt();//输入选项
        if(i==1){
            System.out.println("您可租车的类型及其价目表");//是则进入下一步
            System.out.println("序号\t汽车名称\t租金\t容量");

            for(a=0;a<(pc.length+tc.length+pu.length);a++){
                if(a<pc.length){
                    System.out.println((a+1)+".\t"+pc[a].getCarStyle()+"\t"+
            pc[a].getMoney()+"元/天\t"+"载人："+pc[a].getPeople()+"人");//显示载人车辆
                }
                else if(a<(tc.length+pc.length)&&a>=pc.length){
                    System.out.println((a+1)+".\t"+tc[a-pc.length].getCarStyle()+"\t"+
            tc[a-pc.length].getMoney()+"元/天\t"+"载货："+tc[a-pc.length].getWeight()+"吨");//显示载货车辆
                }
                else{
                    System.out.println((a+1)+".\t"+pu[a-(pc.length+tc.length)].getCarStyle()+"\t"+
                    pu[a-(pc.length+tc.length)].getMoney()+"元/天\t"+"载人："+pu[a-(pc.length+tc.length)].getPeople()+"人"+
                    "载重"+pu[a-(pc.length+tc.length)].getWeight()+"吨");//显示皮卡车辆
                }

            }
            System.out.println("请输入您要租车的数量：(数量上限为：1-"+(pc.length+tc.length+pu.length)+")");
            int j=se.nextInt();//选择租车数量
            if(j>(pc.length+tc.length+pu.length)&&j<1){
                System.out.println("输入有误，请重新输入！");
                j=se.nextInt();
            }else{
                for(int b=1;b<=j;b++){
                    System.out.println("清输入第"+b+"辆车的序号");
                    int k=se.nextInt();//选择车辆
                        switch(k){
                            case 1:
                                style[0]=new String(pc[0].getCarStyle());
                                totalPeople+=pc[0].getPeople();
                                totalMoney+=pc[0].getMoney();
                                break;
                            case 2:
                                style[1]=new String(pc[1].getCarStyle());
                                totalPeople+=pc[1].getPeople();
                                totalMoney+=pc[1].getMoney();
                                break;
                            case 3:
                                style[2]=new String(pc[2].getCarStyle());
                                totalPeople+=pc[2].getPeople();
                                totalMoney+=pc[2].getMoney();
                                break;
                            case 4:
                                style[3]=new String(tc[0].getCarStyle());
                                totalWeight+=tc[0].getWeight();
                                totalMoney+=tc[0].getMoney();
                                break;
                            case 5:
                                style[4]=new String(tc[1].getCarStyle());
                                totalWeight+=tc[1].getWeight();
                                totalMoney+=tc[1].getMoney();
                                break;
                            case 6:
                                style[5]=new String(pu[0].getCarStyle());
                                totalPeople+=pu[0].getPeople();
                                totalWeight+=pu[0].getWeight();
                                totalMoney+=pu[0].getMoney();
                                break;
                        }
                }
                System.out.println("请输入租车的天数：");
                int h=se.nextInt();
                System.out.println("您的账单：");
                if(style[0]!=nullstyle[1]!=nullstyle[2]!=nullstyle[5]!=null){
                    System.out.println("***可载人的车 有：");
                    for(int c=0;c<3;c++){
                        if(style[c]!=null)
                        System.out.print("\t"+style[c]);
                    }
                    if(style[5]!=null)
                        System.out.print("\t"+style[5]);
                }
                else System.out.println("没有选择租取载人车辆！");

                if(totalPeople!=0){

                System.out.println("\t共载人："+totalPeople+"人");

                }
                if(style[3]!=nullstyle[4]!=nullstyle[5]!=null){
                    System.out.println("***可载货的车 有：");
                    for(int d=3;d<5;d++){
                        if(style[d]!=null)
                        System.out.print("\t"+style[d]);
                    }
                    if(style[5]!=null)
                        System.out.print("\t"+style[5]);
                }
                else System.out.println("没有选择租取载货车辆！");

                if(totalWeight!=0){

                    System.out.println("\t共载货："+totalWeight+"吨");

                }
                System.out.println("***租车总价格："+totalMoney*h);

            }
        }else{ 
            System.out.println("谢谢使用！");
            System.exit(0);//否则退出程序

        }

    }
}