text: const express = require('express');
  const path = require('path');
  
  const app = express();
  
  app.use(express.static(path.join(__dirname,'public')));
  app.get('/test',(req, res) => {
    const result = 'fn()'
    res.send(result)
  })
  app.get('/better',(req, res) => {
    // 接受客户端传递过来的函数名称
    // const fnName = req.query.callback;
    // 将函数名称对应的函数调用代码返回给客户端
    // const data = JSON.stringify({name:"张三"});
    // const result = fnName +'('+ data + ')'
    // res.send(result)
    res.jsonp({name:"张三"})
  })
  
  app.listen(3001, () => {
    console.log('Listening on prot 3001')
  })
  
  
  
  