我们什么时候在javascript导入中使用'{}'？ [英] When do we use '{ }' in javascript imports?

问题描述

我正在学习Javascript导入，当我们从另一个JS文件导入项目（函数，对象，变量）时使用花括号时我还不明白。

I am learning Javascript imports and I am yet to understand when we use curly braces while importing items(functions, objects, variables) from another JS file.

import Search from './models/Search';
import * as searchView from './views/searchView';
import { elements, renderLoader } from './views/base'
//elements is an object, renderLoader is a function

推荐答案

import { elements, renderLoader } from './views/base'

是从模块导入单个命名导出所需的方式，在这种情况下，它导入命名导出 元素和 renderLoader 来自 base.js 。

is the way you need to import single, named exports from a module, in this case it is importing named exports elements and renderLoader from base.js.

{elements，renderLoader} 语法在很多情况下只是语法糖（称为 destructuring ）在最新版本的ECMAScript标准中添加。

The { elements, renderLoader } syntax is in many cases just syntactic sugar (called destructuring) added in recent versions of the ECMAScript standard.

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment#Object_destructuring

但在这种情况下，只需获得所需的指定出口。

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/import#Import_a_single_export_from_a_module

请注意，您还可以为您的变量选择新名称，如下所示：

Please note that you can also pick new names for your variables like this:

import { elements as newNameForElements, renderLoader as newNameForRenderLoader } from './views/base'

然后会产生元素导出可用 newNameForElements 等。

which would then make the elements export available as newNameForElements etc.

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