nodejs require用法

$ cat aa.js 
function aa(){
    let a = 1 ;

    let b = 2;
    let c = a + b;
    alert(c);
}

exports.aa = aa;

$ cat app.js 
let a = require(‘./aa.js‘);
a.aa();

$ cat aa.js 
function aa(){
    let a = 1 ;

    let b = 2;
    let c = a + b;
    alert(c);
}

module.exports = aa;

$ 
tanpengfei3@bage:/opt/wks/vue/01_webpack$ cat app.js 
let a = require(‘./aa.js‘);
a();