语法：const {} = variableName，任何人都可以解释或指出我正确的方向 [英] Syntax: const {} = variableName, can anyone explain or point me into the right direction

问题描述

这种语法在JavaScript（ES6可能）中意味着什么：

What does this syntax mean in JavaScript (ES6 probably):

const {} = variablename;

const {} = variablename;

我目前正试图抓住React。在很多例子中，我遇到了这种语法。例如：

I'm currently trying to get a grip of React. In a lot of examples I came across that syntax. For example:

const {girls, guys, women, men} = state;

推荐答案

首先，这与React无关。它是ECMAScript 6的一部分（如果您愿意，还可以使用JavaScript 2015）。

First of all, this has nothing to do with React. It's part of ECMAScript 6 (or JavaScript 2015 if you prefer).

您在此处看到的内容称为解构分配：

What you see here is called Destructuring assignment:

const {girls, guys, women, men} = state;

// Is the same as

const girls = state.girls;
const guys = state.guys;
const women = state.women;
const men = state.men;

在学习React时你可能会遇到类似的模式：

You're probably going to encounter a similar patter while studying React:

import { methodA, methodB } from "my-module";

在这种情况下，你有一个名为 my-module 即公开一些功能。使用语法中的 import {}，您可以选择要导入的函数。请注意，这不是解构赋值，尽管它的工作方式类似。

In this case you have a module called my-module that is exposing some functions. With the import {} from syntax you choose which functions you want to import. Note that this is not destructuring assignment although it works in a similar way.

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