JavaScript 中的 const 和 const {} 有什么区别

2022-01-10 00:00:00 node.js electron javascript destructuring

在学习electron的时候，发现了两种获取BrowserWindow对象的方法.

When I study electron, I found 2 ways of getting BrowserWindow object.

const {BrowserWindow} = require('electron')

和

const electron = require('electron')
const BrowserWindow = electron.BrowserWindow

JavaScript中的const和const {}有什么区别?

What is the difference between const and const {} in JavaScript?

我不明白为什么 const {} 可以工作.我错过了关于 JS 的任何重要内容吗?

I can't understand why the const {} can work. Do I miss anything important about JS?

推荐答案

两段代码是等价的，但第一段使用的是 ES6 解构赋值 要更短.

The two pieces of code are equivalent but the first one is using the ES6 destructuring assignment to be shorter.

下面是一个简单的例子来说明它是如何工作的:

Here is a quick example of how it works:

const obj = {
  name: "Fred",
  age: 42,
  id: 1
}

//simple destructuring
const { name } = obj;
console.log("name", name);

//assigning multiple variables at one time
const { age, id } = obj;
console.log("age", age);
console.log("id", id);

//using different names for the properties
const { name: personName } = obj;
console.log("personName", personName);

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