汽车出租系统java运用数组，继承

好的，这是一个简单的汽车出租系统Java程序的示例，使用了继承和数组。

首先，我们定义一个Car类来表示汽车：

public class Car {
    private String make;
    private String model;
    private int year;
    private double price;

    public Car(String make, String model, int year, double price) {
        this.make = make;
        this.model = model;
        this.year = year;
        this.price = price;
    }

    public String getMake() {
        return make;
    }

    public String getModel() {
        return model;
    }

    public int getYear() {
        return year;
    }

    public double getPrice() {
        return price;
    }

    public String toString() {
        return year + " " + make + " " + model + ", $" + price;
    }
}

然后，我们定义一个RentalCar类来表示出租汽车，它继承自Car类：

public class RentalCar extends Car {
    private boolean rented;

    public RentalCar(String make, String model, int year, double price) {
        super(make, model, year, price);
        rented = false;
    }

    public boolean isRented() {
        return rented;
    }

    public void rent() {
        rented = true;
    }

    public void returnCar() {
        rented = false;
    }

    public String toString() {
        String status;
        if (rented) {
            status = " (rented)";
        } else {
            status = " (available)";
        }
        return super.toString() + status;
    }
}

在RentalCar类中，我们添加了一些特定于租车的方法，如rent()和returnCar()，并添加了一个表示是否已被租赁的变量rented。

现在，我们可以创建一个CarRentalSystem类，用于管理所有的租车：

import java.util.Scanner;

public class CarRentalSystem {
    private RentalCar[] cars;

    public CarRentalSystem(int size) {
        cars = new RentalCar[size];
    }

    public void addCar(int index, RentalCar car) {
        cars[index] = car;
    }

    public RentalCar getCar(int index) {
        return cars[index];
    }

    public void rentCar(int index) {
        cars[index].rent();
    }

    public void returnCar(int index) {
        cars[index].returnCar();
    }

    public void displayCars() {
        for (int i = 0; i < cars.length; i++) {
            System.out.println(i + ": " + cars[i]);
        }
    }

    public static void main(String[] args) {
        CarRentalSystem system = new CarRentalSystem(3);
        system.addCar(0, new RentalCar("Toyota", "Camry", 2020, 50.0));
        system.addCar(1, new RentalCar("Honda", "Accord", 2021, 60.0));
        system.addCar(2, new RentalCar("Nissan", "Altima", 2019, 40.0));

        Scanner scanner = new Scanner(System.in);
        int choice;
        do {
            System.out.println("1. Rent a car");
            System.out.println("2. Return a car");
            System.out.println("3. Display available cars");
            System.out.println("4. Exit");
            System.out.print("Enter your choice: ");
            choice = scanner.nextInt();

            switch (choice) {
                case 1:
                    System.out.print("Enter car number to rent: ");
                    int rentIndex = scanner.nextInt();
                    system.rentCar(rentIndex);
                    break;
                case 2:
                    System.out.print("Enter car number to return: ");
                    int returnIndex = scanner.nextInt();
                    system.returnCar(returnIndex);
                    break;
                case 3:
                    system.displayCars();
                    break;
                case 4:
                    System.out.println("Goodbye!");
                    break;
                default:
                    System.out.println("Invalid choice, try again.");
                    break;
            }
        } while (choice != 4);
    }
}

在CarRentalSystem类中，我们使用了一个RentalCar类型的数组来存储所有的租车，并添加了一些方法来管理这些租车。在main()方法中，我们创建了一些RentalCar对象，并添加到CarRentalSystem类中。然后，我们使用一个简单的菜单来让用户选择租车、还车或显示可用车辆。