// ajax 请求4部曲let xhr = new XMLHttpRequest();xhr.open('GET','/api/user',true);xhr.onload = function () {console.log(xhr.response);
}xhr.send();let express = require('express');let app = express();app.get('/api/user',(req,res)=>{res.json({name:'珠峰架构'})
});app.listen(4000);