在ES6模块中导出多个类

时间:2016-07-12 23:43:22

标签: javascript module export ecmascript-6 babel

我正在尝试创建一个导出多个ES6类的模块。我们假设我有以下目录结构:

my/
└── module/
    ├── Foo.js
    ├── Bar.js
    └── index.js

Foo.jsBar.js各自导出一个默认的ES6类:

// Foo.js
export default class Foo {
  // class definition
}

// Bar.js
export default class Bar {
  // class definition
}

我目前的index.js设置如下:

import Foo from './Foo';
import Bar from './Bar';

export default {
  Foo,
  Bar,
}

但是,我无法导入。我希望能够做到这一点,但是没有找到这些课程:

import {Foo, Bar} from 'my/module';

在ES6模块中导出多个类的正确方法是什么?

6 个答案:

答案 0 :(得分:160)

在您的代码中尝试此操作:

import Foo from './Foo';
import Bar from './Bar';

// without default
export {
  Foo,
  Bar,
}
不过,你也可以这样做:

// bundle.js
export { default as Foo } from './Foo'
export { default as Bar } from './Bar'
export { default } from './Baz'

// and import somewhere..
import Baz, { Foo, Bar } from './bundle'

使用export

export const MyFunction = () => {}
export const MyFunction2 = () => {}

const Var = 1;
const Var2 = 2;

export {
   Var,
   Var2,
}


// Then import it this way
import {
  MyFunction,
  MyFunction2,
  Var,
  Var2,
} from './foo-bar-baz';

export default的区别在于您可以导出内容,并在导入内容时应用名称:

// export default
export default class UserClass {
  constructor() {}
};

// import it
import User from './user'

答案 1 :(得分:12)

希望这会有所帮助:

// Export (file name: my-functions.js)
export const MyFunction1 = () => {}
export const MyFunction2 = () => {}
export const MyFunction3 = () => {}

// Import
import * as myFns from "./my-functions";

myFns.MyFunction1();
myFns.MyFunction2();
myFns.MyFunction3();


// OR Import it as Destructured
import { MyFunction1, MyFunction2 } from "./my-functions";

// AND you can use it like below with brackets (Parentheses) if it's a function 
// AND without brackets if it's not function (eg. variables, Objects or Arrays)  
MyFunction1();
MyFunction2();

答案 2 :(得分:4)

@ webdeb的答案对我不起作用,我在用Babel编译ES6时遇到unexpected token错误,执行命名的默认导出。

然而,这对我有用:

// Foo.js
export default Foo
...

// bundle.js
export { default as Foo } from './Foo'
export { default as Bar } from './Bar'
...

// and import somewhere..
import { Foo, Bar } from './bundle'

答案 3 :(得分:2)

// export in index.js
export { default as Foo } from './Foo';
export { default as Bar } from './Bar';

// then import both
import { Foo, Bar } from 'my/module';

答案 4 :(得分:2)

对于同一classes文件中的多个 js ,从Component扩展@wordpress/element,您可以这样做:

// classes.js
import { Component } from '@wordpress/element';

const Class1 = class extends Component {
}

const Class2 = class extends Component {
}

export { Class1, Class2 }

并将它们导入另一个js文件中:

import { Class1, Class2 } from './classes';

答案 5 :(得分:-1)

要导出类的实例,您可以使用以下语法:

// export index.js
const Foo = require('./my/module/foo');
const Bar = require('./my/module/bar');

module.exports = {
    Foo : new Foo(),
    Bar : new Bar()
};

// import and run method
const {Foo,Bar} = require('module_name');
Foo.test();