有一些冗余代码, 只是实现了功能

package com.dada;

public class Cars {
//定义子类应该有的属性
public String carName; //车名
public int id, carryMan; //编号, 载客量
public float unitPrice, carryGoods; //每日价格, 载货量
}

package com.dada;

public class Bus extends Cars{
//创建有参构造方法
public Bus(int id, String carName, float unitPrice, int carryMan ) {
this.carName = carName;
this.id = id;
this.carryMan = carryMan;
this.unitPrice = unitPrice;
}
}

package com.dada;

public class Truck extends Cars {
public Truck( int id, String carName, float unitPrice, float carryGoods ){
this.carName = carName;
this.id = id;
this.unitPrice = unitPrice;
this.carryGoods = carryGoods;
}
}

package com.dada;

public class PickUp extends Cars {
public PickUp( int id, String carName, float unitPrice, int carryMan, float carryGoods ){
this.carName = carName;
this.id = id;
this.carryMan = carryMan;
this.unitPrice = unitPrice;
this.carryGoods = carryGoods;
}
}

package com.dada;
import java.util.Scanner;

public class Users {
static Cars[] cars;
static int[] carsId;
static int days;
static float allMoney;
static int allPersons;
static float allGoods;
public static void main(String[] args) {
// TODO Auto-generated method stub
System.out.println("欢迎进入哒哒租车系统:\n 是否要租车:1 是 0 否");
Scanner input = new Scanner(System.in);
int entry = input.nextInt();
if(entry == 1) {
//罗列车目类型
Users use = new Users();
System.out.println("您可租车的类型及价目表:\n 编号\t 车名\t 单价\t\t 容量");
use.getCars();
System.out.println("请选择要租车的数量:");
int numbers = input.nextInt();
//调用租车数量
use.carsNum(numbers);
System.out.println("输入要租的天数: ");
days = input.nextInt();
//调用打印结果
use.display();
}

}
//车目类型
public void getCars(){
    Bus audi = new Bus(1, "奥迪a4", 500f, 5);
    Bus mzd = new Bus(2, "马自达6", 400f, 5);
    Truck shj = new Truck(3, "松花江", 400f, 4);
    Truck ywk = new Truck(4, "依维柯", 1000f, 20);
    PickUp mq = new PickUp(5, "猛禽", 1200f, 5, 5);
    PickUp cc = new PickUp(6, "长城", 600f, 5, 3);
    Cars cars[] = {audi, mzd, shj, ywk, mq, cc};
    for(Cars car:cars){
        if(car.getClass() == Bus.class) {
            System.out.println(car.id + "\t" + car.carName + "\t" + car.unitPrice + "/天\t\t" + car.carryMan + "人");
        } else if(car.getClass() == Truck.class) {
            System.out.println(car.id + "\t" + car.carName + "\t" + car.unitPrice + "/天\t\t" + car.carryGoods + "吨");
        } else if(car.getClass() == PickUp.class) {
            System.out.println(car.id + "\t" + car.carName + "\t" + car.unitPrice + "/天\t\t" + car.carryMan + "人," + car.carryGoods + "吨");
        }
    }
}
//租车数量
void carsNum(int numbers) {
    //选择每辆车的编号组成的数组
    Scanner input = new Scanner(System.in);
    //定义数组长度
    carsId = new int[numbers];
    for(int i = 1; i <= numbers; i++) {
        System.out.println("请选择第" + i + "辆车的编号");
        int carId = input.nextInt();
        carsId[i - 1] = carId;
    }
}
//计算并打印
void display(){
    Bus audi = new Bus(1, "奥迪a4", 500f, 5);
    Bus mzd = new Bus(2, "马自达6", 400f, 5);
    Truck shj = new Truck(3, "松花江", 400f, 4);
    Truck ywk = new Truck(4, "依维柯", 1000f, 20);
    PickUp mq = new PickUp(5, "猛禽", 1200f, 5, 5);
    PickUp cc = new PickUp(6, "长城", 600f, 5, 3);
    Cars cars[] = {audi, mzd, shj, ywk, mq, cc};
    StringBuilder person=new StringBuilder();
    StringBuilder goods=new StringBuilder();

    for(Cars car:cars) {
        for(int id:carsId) {
            if(id == car.id) {
                allMoney += car.unitPrice;
                if(car.getClass() == Bus.class) {
                    person.append(car.carName + " ");
                    allPersons += car.carryMan;
                }
                if(car.getClass() == Truck.class) {
                    goods.append(car.carName + " ");
                    allGoods += car.carryGoods;
                }
                if(car.getClass() == PickUp.class) {
                    person.append(car.carName + " ");
                    allPersons += car.carryMan;
                    goods.append(car.carName + " ");
                    allGoods += car.carryGoods;
                }
            }
        }
    }
    allMoney = allMoney * days;
    System.out.println("可载人的车有: \n" + person +"\n 可载货的车有: \n" + goods);
    System.out.println("载人总数: \n" + allPersons + "\n 载货总量: \n" + allGoods);
    System.out.println("总金额: \n" + allMoney);
}

}