ESM 模块化

default

// mod/index.js
export default {};
// use.js
import mod from "./mod";

具名

// mod.js
export const a = "a";
export const b = 222;
// use.js
import { a, b } from "./mod.js";

联合使用

// mod.js
export const a = "a";
export default [];
// use.js
import arr, { a } from "./mod.js";
Array.isArray(arr); //true
a === "a"; //true

统一导出导入

// mod.js
const a = "a";
const b = 222;
export { a, b };
export default Array;
// use.js
import * as mod from "./mod.js";
mod.a === "a"; //true
mod.b === 222; //true
mod.default instanceof Array; //true

转发

// mod.js
export const a = "a";
export default [];
// forward.js
export { default as arr } from "./mod.js";
// use.js
import { arr } from "./forward.js";

import.meta

// mod.js
import.meta.xxx = "xxx";
export default [];
// use.js
import mod from "./mod.js";
import.meta.xxx === "xxx"; //true

动态引入

// mod.js
export const a = "a";
export default [];
// use.js
import("./mod.js").then((mod) => {
  mod.a === "a"; //true
  Array.isArray(mod.default); //true
});

别名

mod.js

const a = {};
export { a as b };

use.js

import { b as a } from "mod";