存储对象到数组帮助Java [英] Storing Object Into Array Help Java

问题描述

我试图做一个预约项目，你可以添加，显示，删除约会。

I am trying to make a appointment project which you can add, display, delete appointments.

我有三类： UserInput ，预约，计划。

• UserInput ：只是推动用户进入任何（ INT ，双等）


• 预约：已set和get方法。两个构造，的toString 和方法，该用户的 UserInput 类，然后使用set方法与输入的值。


• 计划：在课堂上，我不得不删除，显示和添加约会的选项。

• UserInput: is just to promote the user to enter whatever ( int, double, etc..)
• Appointment: has set and get methods. two constructor, toString, and a method that user the UserInput class and then use the set methods with the value entered.
• Planner: is the class I have the options to delete, display and add appointments.

我创建预约的数组对象，在计划类20个插槽私人约会[]数组=新约会[20];。

I created an array object of Appointment with 20 slots in the planner class.private Appointment[] array = new Appointment[20];

我现在面临的问题是将对象添加到阵列。我试图在构造函数中的一些插槽分配默认值。我显示了阵列和它的工作。现在我做了调用方法和分配曾被输入什么 inputAppointment （即要求用户输入然后调用设置方法的类）的方法。

The problem I am facing is with adding objects to the array. I tried assigning default value for some slots in the constructor. I displayed the array and it worked. Now I made a method to call the inputAppointment( the class that ask the user to input then call the set methods ) method and assign what ever was inputted.

该方法看起来像

public void addAppointment() {
    Appointment object = new Appointment();
    object.inputAppoitment();
    array[5] = object;
}

inputAppointment方法

inputAppointment method

public void inputAppoitment() {
    UserInput Object = new UserInput();

    System.out.println("Enter The Month");
    setMonth(Object.getString(3, 3));
    System.out.println("Enter The Day");
    setDay(Object.getInt(1, 31));
    System.out.println("Enter The Hour");
    setHour(Object.getInt(1, 24));
    System.out.println("Enter The Minute");
    setMinute(Object.getInt(1, 59));
    System.out.println("Enter A Short Description");
    setMessage(Object.getString(5, 40));

}

我跑了方法，那么显示的数组，但加入什么！
我可以做似乎太复杂，但如果你想要的东西更清楚我将很高兴来解释。

I ran the method then displayed the array but nothing was added! I may seem made it too complicated but if you want something more clear I would be happy to explain.

更新：
我打过电话从主不是我的菜单循环的方法，它似乎工作。
这是我的菜单看起来怎么样。

Update: I tried calling the method from main not my menu loop and it seems to work. this is how my menu look like.

while (true) {
        System.out.println("\nPlease Choose.");
        System.out.println("A)dd Appointment , D)elete Appointment , L)ist Appointment , E)xit");
        char userChoice = UserInput.getChar();
        Planner obj = new Planner();
        if (userChoice == 'A' || userChoice == 'a') {
            obj.addAppointment();
        }
        if (userChoice == 'D') {

        }
        if (userChoice == 'L') {
            obj.listAppointment();
        }
        if (userChoice == 'E') {
            break;
        }

    }

谢谢大家。

推荐答案

问题是对象的范围。

public void addAppointment() {
     // this would be unreferenced when the method finishes
    Appointment object = new Appointment();
    object.inputAppoitment();
    array[5] = object; // so now array[5] refers to object;
} // object is no longer in scope, array[5] no longer has a reference to it

我会重写你的code是这样的：

I would rewrite your code like this:

public Appointment addAppointment() {
    // we have to access the reference when the method returns
    Appointment object = new Appointment();
    object.inputAppoitment();
    return object; // we return the reference to object and asign it into array[5]
}

我们叫它是这样的：

array[5] = addAppointment();

这篇关于存储对象到数组帮助Java的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！