function in js, two parameters, id and data 
 import axios from "axios"; 
 import qs from" qs"; 
 export let updateBook= (id,data) = > {
 return axios.put ( / book?id=$ {id} , qs.stringify (data)); 
}; 
 after sending the request, no data was obtained and an error was reported 
case "PUT":
     if(id){
       let str = "";
       req.on("data",chunk=>{
         str+=chunk;
         console.log(str);
       });
       console.log(str);
       req.on("end",()=>{
         let book = JSON.parse(str);
         read(function (books) {
           books = books.map(item=>{
             if(item.bookId === id){
               return book
             }
             return item;
           });
           write(books,function () {
             res.end(JSON.stringify(book));
           })
         });
       })
     }
     break;
     console:
     
 
 
