语法:const {} = variableName，谁能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

这个语法在 JavaScript 中是什么意思(可能是 ES6):

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

const {} = 变量名;

const {} = variablename;

我目前正在尝试掌握 React.在很多例子中，我都遇到过这种语法.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(或 JavaScript 2015，如果您愿意)的一部分.

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赋值:

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;

您在学习 React 时可能会遇到类似的情况:

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

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

在这种情况下，您有一个名为 my-module 的模块，它公开了一些函数.使用 import {} from 语法，您可以选择要导入的函数.请注意，这不是解构赋值，尽管它以类似的方式工作.

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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