在node中如何使用 ES6

npm install babel-core --save-dev

npm install babel-register --save-dev

{
 "presets" : ['es2015']
}

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

require('babel-register');
require('./app.js')

import express from 'express';

class Person {
  say() {
    console.log('hello');
  }
}

let app = express();
app.get('/', (res, req) => {

})
app.listen(3000, (res) => {
  new Person().say();
});