在 ES6 javascript 中 at 符号 (@) 有什么作用?(ECMAScript 2015) [英] What does the at symbol (@) do in ES6 javascript? (ECMAScript 2015)

问题描述

我正在查看一些 ES6 代码，但我不明白 @ 符号放在变量前面时的作用.我能找到的最接近的东西与私有字段有关?

I'm looking at some ES6 code and I don't understand what the @ symbol does when it is placed in front of a variable. The closest thing I could find has something to do with private fields?

我从 redux 库 中查看的代码:

Code I was looking at from the redux library:

import React, { Component } from 'react';
import { bindActionCreators } from 'redux';
import { connect } from 'redux/react';
import Counter from '../components/Counter';
import * as CounterActions from '../actions/CounterActions';

@connect(state => ({
  counter: state.counter
}))
export default class CounterApp extends Component {
  render() {
    const { counter, dispatch } = this.props;
    return (
      <Counter counter={counter}
               {...bindActionCreators(CounterActions, dispatch)} />
    );
  }
}

这是我在该主题上找到的一篇博客文章:https://github.com/zenparsing/es-private-字段

Here is a blog post I found on the topic: https://github.com/zenparsing/es-private-fields

在这篇博文中，所有示例都在类的上下文中 - 当符号在模块中使用时，这意味着什么?

In this blog post all the examples are in the context of a class - what does it mean when the symbol is used within a module?

推荐答案

这是一个装饰器.这是一个要添加到 ECMAScript 的建议.有多个 ES6 和 ES5 等效示例:javascript-decorators.

It's a decorator. It's a proposal to be added to ECMAScript. There are multiple ES6 and ES5 equivalent examples on: javascript-decorators.

装饰器动态地改变函数、方法或类的功能，而无需直接使用子类或更改被装饰函数的源代码.

Decorators dynamically alter the functionality of a function, method, or class without having to directly use subclasses or change the source code of the function being decorated.

它们通常用于控制访问、注册、注释.

They are commonly used to control access, registration, annotation.

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