How does nodejs extract the key-value pair of formData inside?

  node.js, question

I use ajax to send FormData data data:

window.onload = function(){
 document.getElementById("sub").addEventListener("click",function(e){
 var myFormData = new FormData(document.getElementById("myform"));
 var xhr = new XMLHttpRequest();
 xhr.open("post","http://localhost:8008/");
 xhr.onload = function(){
 if(xhr.status === 200){
 Log ('request succeeded');
 bracket
 bracket
 xhr.send(myFormData);
 },false);
 bracket

The server written by nodejs (partial code):

req.on('data',function(chunk){
 Dataplus = chunk;
 });
 req.on("end",function(){
 console.log(data);
 })

It was found that data was ultimately

------WebKitFormBoundaryT7SKm0RPi5FrxsAN
 Content-Disposition: form-data;  name="name"
 
 Xiao Ming
 ------WebKitFormBoundaryT7SKm0RPi5FrxsAN
 Content-Disposition: form-data;  name="password"
 
 ffff
 ------WebKitFormBoundaryT7SKm0RPi5FrxsAN--

How should I resolve the name and password inside

var http = require('http');
 var multiparty = require('multiparty');
 
 http.createServer(function (req, res) {
 var form = new multiparty.Form();
 form.parse(req, function (err, fields, files) {
 console.log(fields);
 });
 }).listen(3000);

Can be usedmultipartyTo parse form-data data