创建下一个对象并将其放入 ArrayList

Question

好的，所以我觉得解释我的意思可能非常困难，但是，我会尝试。所以，基本上我想做的是 CREATE 下一个 OBJECT 和 PLACE 它在 ARRAYLIST 使用 USER INPUT.

是否可以使用ArrayList的计数来实现？假设我的构造函数允许传递一个名称以创建一个对象，我是否可以向用户询问该名称并稍后使用它来这样做，然后将它传递给已经创建的 ArrayList？

我觉得我无法正确解释我的意思，英语不是我的母语，抱歉。 :)

public class Voter 
{ 
   private String name;
   private ArrayList<Voter> voters;

   public Voter(){
      this.name = "";
      voters = new ArrayList();
   }

   public Voter(String name)
   {
      this.name = name;
      voters = new ArrayList<>();
   }

   public void add(Voter v)
   {
      if (!this.voters.contains(v))
      {
          this.voters.add(v);
      }
   }

}



public static void main(String[] args)
{   
   Voter v1 = new Voter("Admin");

   Voter v = new Voter();
   v.add(v1);

   displayMenu();

   int option = getInt("Enter Option:", 0, 3);
   while (option != END)
   {
      if (option == 1)
      {
         doOption1();
         int count = v.countArray(v);
      }
   }
}

public static void displayMenu()
{
    System.out.println("\nSample Menu of Options");
    System.out.println("0. Exit this menu");
    System.out.println("1. Option 1");
}

public static void doOption1()
{
   System.out.println("Please, enter the below details to register for 
   voting system.");
   System.out.println("Full name");
   String name = keyboard.nextLine();
   //THIS IS WHERE I WANT TO CREATE A NEW OBJECT AND PUT IT AS AN ELEMENT OF
   //MY Voter ARRAYLIST
}

public static int getInt(String prompt, int min, int max)
{
    System.out.print(prompt);
    int value = keyboard.nextInt();
    while ((value < min) || (value > max))
    {
        System.out.println("Invalid - [" + min + "," + max + "] only");
        System.out.print(prompt);
        value = keyboard.nextInt();
    }
    keyboard.nextLine();
    return value;
}

Answer 1

使用您当前的算法，要将项目添加到 Voter 对象的 ArrayList，您所要做的就是首先重建 [=] 的方法定义15=] 到下面的方法。

public static void doOption1(Voter voter){
      System.out.println("Please, enter the below details to register for voting system.");
      System.out.println("Full name");
      String name = keyboard.nextLine();
      voter.add(new Voter(name)); // you could validate name before constructing the object if you see fit.
}

完成后，您需要更改此代码：

while (option != END){
    if (option == 1){
       doOption1();
       int count = v.countArray(v);
    }
}

对此：

while (option != END){
    if (option == 1){
       doOption1(v); // notice the argument
       int count = v.countArray(v);
    }
}

创建下一个对象并将其放入 ArrayList

Creating next object and placing it in an ArrayList

java

class

arraylist

object

instances