node.js中使用Export和Import的方法

class Point {  constructor(x, y) {    this.x = x;    this.y = y;  }  add (){    this.x = this.x ? this.x : 1;    this.y = this.y ? this.y : 2;    return this.x + this.y;  }}const PI = 3.1415926;exports.Point = Point;exports.PI = PI;let a = new Point();console.log(a.add());

let {Point,PI} = require('./test.js');class Point2 extends Point{  //add();}let b = new Point2();console.log(b.add());console.log(PI);

 "babel": {  "presets": ["es2015"] }, "scripts": {  "start": "node app/51job.js",  "build": "babel src -d app" },

npm install --save-dev babel-clinpm install babel-preset-es2015 --save-dev