Upload and handle file in ReactJs and NodeJs using FormData.

npx create-react-app <YOUR_APP_NAME>

import { useState } from "react";import "./../App.css";const FileUpload = () => { const [selectedFile, setSelectedFile] = useState(); const [isFilePicked, setIsFilePicked] = useState(false); const changeHandler = (event) => {  setSelectedFile(event.target.files[0]);  event.target.files[0] && setIsFilePicked(true); }; const handleSubmission = () => {  // HANDLING FILE AS SENDING FILE INTO BACKEND  if (!isFilePicked) return;  const formData = new FormData();  formData.append("File", selectedFile);   // ALSO ADD RANDOM VALUE IF YOU WANT LIKE STRING , OBJECT OR      ARRAY  formData.append("carDetail", {   car: "honda",   engine: "1498 cc",   fuel_Type: "Petrol & Diesel", });// API CALL fetch("http://localhost:3001/", {  method: "POST",  body: formData, }) .then((response) => response.json()) .then((result) => {  console.log("Success:", result); }) .catch((error) => {   console.error("Error:", error);  }); };return ( <div className="App"> <input type="file" name="file" onChange={changeHandler} />  <div>   <button onClick={handleSubmission}>Submit</button>  </div> {isFilePicked ? ( <div>  <p>Filename: {selectedFile.name}</p>  <p>Filetype: {selectedFile.type}</p>  <p>Size in bytes: {selectedFile.size}</p>  <p>   lastModifiedDate:{" "}   {selectedFile.lastModifiedDate.toLocaleDateString()}  </p> </div> ) : ( <div>  <p>Select a file</p>  </div> )} </div> );};export default FileUpload;

var express = require(express);const upload = require(express-fileupload);var cors = require(cors);var app = express();//MIDDLEWARESapp.use(upload());app.use(cors());//ROUTE DEFINEapp.post(/, async function (req, res) { try {  // IN REQ.FILES.YOUR_FILE_NAME WILL BE PRESENT  const file = req.files;  const bodyData = req.body;  // console.log(file);  // console.log(bodyData);  res.status(200).send({  message: FILE RECEIVED!, }); } catch (error) { res.send(ERROR); }});var PORT = 3001;app.listen(PORT, function () { console.log(Server is running on PORT:, PORT);});