How to implement import and export in javascript (code attached)-JS Tutorial-php.cn

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How to implement import and export in javascript (code attached)

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Aug 22, 2018 pm 05:56 PM

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The content of this article is about the implementation of import and export in JavaScript (with code). It has certain reference value. Friends in need can refer to it. I hope it will be helpful to you.

Node mode import and export

A JavaScript file can export exprots countless variables, functions, and objects, but require( );, you only need to load the JS file once. Therefore, after being invisible, a top-level namespace will be added.

Importing an empty module is an empty object, and a module is an object.

Export method:

exports, export the entire formula
##module. exports, export assignment part

Import method:

reuire()

// 导出一个变量
exports.a = 10;

// 导入该变量
let b = require('./export')

// 导入的形式 `console.log(b)`输出导入的值：
// { a: 10 }

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// 导出一个变量，直接需要变量值使用.
// module.exports = 'name';

// 导入该变量
let b = require('./export')

// 导入的形式 `console.log(b)`输出导入的值：
// name

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// 导出对象
module.exports = {
  name1: 123,
  name2: 456
}

// 导入该变量
let b = require('./export')

// 导入的形式 `console.log(b)`输出导入的值：
// { name1: 123, name2: 456 }

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// 导出对象
exports.msg = {
  name1: 1,
  name2: 2
}

// 导入该变量
let b = require('./export')

// 导入的形式 `console.log(b)`输出导入的值：
// { msg: { name1: 1, name2: 2 } }

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// 导出函数
exports.showMsg = function () {
}

// 导入该变量
// let b = require('./export')

// 导入的形式 `console.log(b)`输出导入的值：
// { showMsg: [Function] }

// 在 引用结果 需要  通过  变量 引用对象 执行
// var b= require();
// b.showMsg();

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// 导出函数
module.exports = function () {
}

// 导入该变量
let b = require('./export')

// 导入的形式 `console.log(b)`输出导入的值：
// [Function]

// 引入文件的 变量  直接执行

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Commonly used export methods for objects and functions:

module.exports##ES6 and TS import and export

Export:

export

Import:import
Note:

as
, the variable names are the same
default
Export, you can use any variable name when importing

export default

Default export module Cannot use {}Object export##

// 导出一个常量
export const foo = Math.sqrt(2)

// 导入
import { foo } from './export'
import * as Tools from './export' // 使用 Tools.foo

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function myFunction () {}
// 导出已经声明的函数
export { myFunction }

导入
import { myFunction } from './export'

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// 多个导出
export function cube(x: number): number {
    return x * x * x
}
const foo: number = Math.PI * Math.sqrt(2)
export { foo } // 导出多个

// 导入
import { cube, foo } from './export'

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// 导出函数
export default function () {}
export default function fun () {}

// 导入
import myFunction from './export' // 可以取任意变量名
// 如果导出默认，定义函数名或者变量名，或者类名
// 导入的时候可以写和原来相同名字，也可以取任意变量名

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// 导出类
export default class {}

// 导入
import Test from './export'

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A file (module) can only have one default export, which can be a class, function, object, etc.

Import the contents of the entire module and insert the

export

variable in the current scope, including all export bindings in the

export file (including export default):

// 导出多个模块
export function query () {}
export function update () {}

// 导入
import * as API from './export'

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Import the entire module as an additional function, but do not import the exported members of the module:

import 'my-module'

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Related recommendations:

excel import and export

Oracle import and export problems

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