父类
package com.dadazuchu;
//父类
public abstract class Car {
protected String carName;
protected int rentPrice;
protected int passengerCapacity;
protected int goodsCapacity;
//构造四个方法
public String getcarName(){
return carName;
}
public int getrentPrice(){
return rentPrice;
}
public int getpassenger(){
return passengerCapacity;
}
public int getgoods(){
return goodsCapacity;
}

}
子类
package com.dadazuchu;

public class Pickup extends Car {
//子类对象初始化
Pickup(String carName,int rentPrice,int passengerCapacity,int goodsCapacity){
this.carName=carName;
this.rentPrice=rentPrice;
this.passengerCapacity=passengerCapacity;
this.goodsCapacity=goodsCapacity;
}

}
package com.dadazuchu;

public class Passenger extends Car {
//子类对象初始化
Passenger(String carName,int rentPrice,int passengerCapacity){
this.carName=carName;
this.rentPrice=rentPrice;
this.passengerCapacity=passengerCapacity;

}

}
package com.dadazuchu;

public class Goods extends Car {
//子类对象初始化
Goods(String carName,int rentPrice,int goodsCapacity){
this.carName=carName;
this.rentPrice=rentPrice;
this.goodsCapacity=goodsCapacity;
}
}

主函数
package com.dadazuchu;
import java.util.*;
public class Initial {

public static void main(String[] args) {
    // TODO Auto-generated method stub

// 租车类型及价格表，创建父类数组调用子类对象
Car[] carforRent={
new Passenger("奥迪A4", 500, 4),
new Passenger("马自达6", 400, 4),
new Pickup("皮卡雪",450,4,2),
new Passenger("金龙",800,20),
new Goods("松花江", 400, 4),
new Goods("依维柯", 1000, 20)};
System.out.println("欢迎使用嗒嗒租车系统！");
System.out.println("您是否要租车：1是，0否");
Scanner sn=new Scanner(System.in);
String input=sn.nextLine();
int num=1;
if(input.equals("1")){
System.out.println("您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");
//新建父类 Car newcar来遍历父类数组carforRent

        for(Car newcar:carforRent){
            //如果数组内有Passenger对象，输出该对象的属性
            if(newcar instanceof Passenger){
                System.out.println(num+".\t"+newcar.carName+"\t"+newcar.rentPrice+"元/天"+"\t"+"载人:"+newcar.passengerCapacity+"人");
                num++;}
            //如果数组内有Pickup对象，输出该对象的属性
            if(newcar instanceof Pickup){
                System.out.println(num+".\t"+newcar.carName+"\t"+newcar.rentPrice+"元/天"+"\t"+"载人:"+newcar.passengerCapacity+"人"+newcar.goodsCapacity+"吨");
                num++;}
            //如果数组内与Goods对象，输出该对象的属性
            if(newcar instanceof Goods){
                System.out.println(num+".\t"+newcar.carName+"\t"+newcar.rentPrice+"元/天"+"\t"+"载人:"+newcar.goodsCapacity+"吨");
                num++;}

    }
    System.out.println("请输入您要租汽车的数量:");
    int Nums=sn.nextInt();//汽车使用量
    //判断数量的可行性
    if(Nums<=0){
        System.out.println("您的输入有误，请重新输入！");
        System.out.println("请输入您要租汽车的数量:");
        Nums=sn.nextInt();
    }
    //这里用把输入值Nums数组化
    int[] carNums=new int[Nums];
    for(int i=0;i<carNums.length;i++){
        System.out.println("请输入第"+(i+1)+"辆车的序号");
        carNums[i]=sn.nextInt();
        //判断输入序号的可行性
        if(carNums[i]>6||carNums[i]<0){
            System.out.println("您的输入有误，请重新输入第"+(i+1)+"辆车的序号");
            if(i>=0){
                i--;
            }else{
                i=0;
            }
            continue;
        }

    }
    System.out.println("请输入租车天数:");
    int days=sn.nextInt();
    //判断输入的天数的可行性
    if(days<=0){
        System.out.println("您的输入有误，请重新输入！");
        System.out.println("请输入租车天数:");
        days=sn.nextInt();
    }
    int Sumcountpeople=0;
    int Sumcoutgoods=0;
    int rent=0;
    System.out.println("您的账单:\n***可载人的车有:");
    //利用for（）{}来遍历父类数组对应的子类对象
    for(int i=0;i<carNums.length;i++){
        //通过if来判断父类数组是否跟子类对象相同
        if((carforRent[carNums[i]-1]instanceof Passenger)||(carforRent[carNums[i]-1]instanceof Pickup)){
            System.out.println(carforRent[carNums[i]-1].carName+"\t");
            //通过if来判断父类数组是否跟子类对象相同
        if((carforRent[carNums[i]-1])instanceof Passenger){
            Sumcountpeople=Sumcountpeople+
           ((Passenger)carforRent[carNums[i]-1]).getpassenger();}//调用子类对象的方法
    //通过if来判断父类数组是否跟子类对象相同
        if((carforRent[carNums[i]-1])instanceof Pickup){
            Sumcountpeople=Sumcountpeople+
            ((Pickup)carforRent[carNums[i]-1]).getpassenger();}//调用子类对象的方法

        }

    }System.out.println("共载人："+Sumcountpeople+"人！");

    System.out.println("您的账单:\n***可载货的车有:");
    //利用for（）{}来遍历父类数组对应的子类对象
    for(int i=0;i<carNums.length;i++){
        //通过if来判断父类数组是否跟子类对象相同
        if((carforRent[carNums[i]-1]instanceof Goods)||(carforRent[carNums[i]-1]instanceof Pickup)){
            System.out.println(carforRent[carNums[i]-1].carName+"\t");
            //通过if来判断父类数组是否跟子类对象相同
        if((carforRent[carNums[i]-1])instanceof Goods){
               Sumcoutgoods=Sumcoutgoods+
              ((Goods)carforRent[carNums[i]-1]).getgoods();}
            //通过if来判断父类数组是否跟子类对象相同
        if((carforRent[carNums[i]-1])instanceof Pickup){
            Sumcoutgoods=Sumcoutgoods+
            ((Pickup)carforRent[carNums[i]-1]).getgoods();}

        }

    }System.out.println("共可载货："+Sumcoutgoods+"吨！");
    for(int i=0;i<carNums.length;i++){
        rent=rent+carforRent[carNums[i]-1].getrentPrice();
    }
    rent=rent*days;
    System.out.println("***租车总价格："+rent+"元！");

    }else if(input.equals("0")){
        System.out.println("谢谢光临");
        return;
    }else if(!input.equals("1")&&!input.equals("0")){
        System.out.println("您的输入错误！");
        Initial sys1=new Initial();
        sys1.main(null);
    }
}

}