什么是用于存储对象的对象和计数器的数据结构

I need to store some entity object + counter of each groups entities objects. How can I do this?

我需要存储每个组实体对象的一些实体对象+计数器。我怎样才能做到这一点?

3 个解决方案

#1

If the counter variable is not a part of the object itself, you can use Map<Object,Integer> as other answers suggest. However, keep in mind that you can use any collection or list if the counter is a part of the object data. Then you will update the counter with setters. Alternatively, updating the counter within particular constructors of various classes may also be a preferred way.

如果计数器变量不是对象本身的一部分,则可以使用Map ,integer>

class Data
{
  int counter = 0;

  Data()
  {
    counter++;
  }
}

#2

You can use a Map

您可以使用地图

Map<Object, Integer> map = new HashMap<Object, Integer>();

Here, Object is your key and Integer is your count .

在这里,对象是你的关键,整数是你的计数。

Your keys should be unique in the HashMap.

您的密钥在HashMap中应该是唯一的。

As it uses hashing, it will help in efficient retrieval of your objects while searching.

因为它使用散列,它将有助于在搜索时有效地检索对象。

#3

Any Map will do. Alternatively if you're not interested in learning about new classes simply use a matrix.

任何地图都可以。或者,如果您对学习新课程不感兴趣,只需使用矩阵即可。

int matrix[][]=new int[10][10];

int matrix [] [] = new int [10] [10];

#1