Question

我试着：

在Car。

Main

将对象作为参数发送到carOwners类。
从main打印整个carOwners数据。

将打印

Name和Address，但不会打印Car。

我的代码出了什么问题？

public class TestProgram {
    public static void main(String [] args){
        Car Saab = createCar();
        carOwners guy = createCarOwners (Saab);
        printAll(guy);
    }

    public static Car createCar (){
        //user input a, b, c, d
        Car temporary = new Car (a, b, c, d);
        return temporary;
    }
    public static carOwners createCarOwners (Car x){
        //user input a, b
        Car c = x;
        carOwners temporary = new carOwners (a, b, c);
        return temporary;
    }

    public static void printAll (carOwners x){
        x.printCarData();
        x.printNameAddress();
    }
}

public class Car {
    private String model;
    private String Year;
    private String licensePlate;
    private String color;

    public Car (String x, int y, String z, String q){
        model = x;
        Year = y;
        licensePlate = z;
        color = q;
    }
}

public class carOwners {
    private String name;
    private String address;
    private Car TheCar;

    public carOwners (String n, String a, Car b){
        name = n;
        address = a;
        TheCar = b;
    }

    public void printNameAddress(){
        System.out.println();
        System.out.println(name);
        System.out.println(address);
    }

    public void printCarData(){
        System.out.println(TheCar);
    }
}

Answer 1

覆盖Car，因此您可以自定义public String toString(){ return "Model :" + this.model + ",Year :" + year; }

的输出格式

{{1}}

Answer 2

你的问题在这里：

public void printCarData(){
        System.out.println(TheCar);
    }

您想要打印一个对象。这不起作用，因为Java使用toString-Method。如果你想这样做，你必须覆盖toString（） - 你的汽车类的方法：

public String toString()
{
     return "CarModel: " + this.model + ", Production Year: " + year;
}

对象作为参数

2 个答案: