ES模块化导入和导出

    //1.导入的{}中定义的变量    import{flag,sum} from"./asd.js";    //在asd.js中定义 flag 和 sum        if(flag){        console.log('Im gentle')        console.log(sum(1,2));    }        //2.间接导入export定义的变量    import {num1,height} from"./dfg.js        console.log(num1);    console.log(height);        //3.导入export的function/class    import {mul,person} from"./jkl.js";        console.log(mul(10,20));        const p = new person();    p.run()        //4.导入export default 中的内容    import addr from ".oiu.js";        addr('hello')        //5.对立全副导入    import * as qwe from './qwe.js'        console.log(qwe.flag);    console.log(qwe.height)