(二)21.Module模块化19-08-16

lesson17.js

export let A=123;//导出语句用export

export function test() {
  console.log('test');
}

export class Hello{
  test(){
    console.log('class');
  }
}

index.js

// import {A,test,Hello} from './class/lesson17';
// console.log(A,test,Hello);
// import {A} from './class/lesson17';
//console.log(A);
import * as lesson from './class/lesson17';// *符号代表导入所有内容，lesson是起的别名
console.log(lesson.A,lesson.test);

以上方式不建议
建议以下方式
index.js

import Lesson17 from './class/lesson17';
console.log(Lesson17.A);

lesson17.js

let A=123;
let test=function(){
  console.log('test');
}
class Hello{
  test(){
    console.log('class');
  }
}

export default {
  A,
  test,
  Hello
}