我对JavaScript还很陌生，但对Java了解很多。我试图通过做一些小项目来学习基础知识，以便理解这门语言和代码。在Java中，我经常与将数据从映射存储在JSON文件中并在程序启动时将JSON文件加载到映射中进行交互。
以下是Java的示例：
```java
public Map<Integer, Client> example = new HashMap<>();

public class Client {
    private String username;
    private String password;
    private String host;
    public Client(String username, String password, String host) {
        this.username = username;
        this.password = password;
        this.host = host;
    }
    public String getPassword() {
        return password;
    }
    public String getHost() {
        return host;
    }
    public String getUsername() {
        return username;
    }
}

var price = new Map();

<details>
<summary>英文:</summary>
I&#180;m quite new to Javascript, but know a lot about Java. Im trying to learn the basics by doing little projects, for understanding the language and code. In Java, i worked a lot with storing data from maps in json-files and, when you start the programm, the json file loads the data into the map. 
An example for Java: 
    public Map&lt;Integer, Client&gt; example = new HashMap&lt;&gt;();
Herefor the Client class :
    public class Client {
    private String username;
    private String password;
    private String host;
    public Client(String username, String password, String host) {
        this.username = username;
        this.password = password;
        this.host = host;
    }
    public String getPassword() {
        return password;
    }
    public String getHost() {
        return host;
    }
    public String getUsername() {
        return username;
    }
    }
I want to do the same thing, but now in Javascript. My map looks like that:
    var price= new Map();
Like the Java example above, I want to load such a Map into a json file and want to load the data from the json file into my map.
Could somebody proivde me with a good example of code, how to store data from json in my map ? Even a link for a tutorial would be great!
</details>
# 答案1
**得分**: 2
在JS中，使用普通对象而不是`Map()`更为常见。
例如，假设您有相同的`Client`类：
```js
class Client {
    constructor(username, password, host) {
        this.username = username;
        this.password = password;
        this.host = host;
    }
}
const client1 = new Client('username1', 'password1', 'localhost');
const client2 = new Client('username2', 'password2', 'localhost');

const price = {
    1: client1,
    2: client2
};

const json = JSON.stringify(price);

const price = JSON.parse(json);