ES6 模块化

写法1

// profile.js 导出模块
export var firstName = 'Michael';
export var lastName = 'Jackson';
export var year = 1958;

//useage.js 导入模块
import {firstName, lastName, year} from './profile';
console.log(firstName)

写法2

// profile.js 导出模块
var firstName = 'Michael';
var lastName = 'Jackson';
var year = 1958;
export {firstName, lastName, year};

//useage.js  导入模块
import {firstName, lastName, year} from './profile';
console.log(firstName)

写法3

//helper.js 导出模块
export function getName(){}
export function getYear(){}

//main.js 导入模块
import {getName, getYear} from './helper';
getName()

写法4

//helper.js 导出模块
function getName(){}
function getYear(){}
export {getName, getYear}

//main.js 导入模块
import {getName, getYear} from './helper';
getName()

写法5

// export-default.js
export default function () {
  console.log('foo');
}

// import-default.js
import getName from './export-default'
getName()