Check out example codes for "body parser". It will help you in understanding the concepts better.

Code Example 1

<script>
const bodyParser = require("body-parser");

app.use(bodyParser.urlencoded({extended:true}));
  
app.post("/", function(req, res){
  let firstName = req.body.fNAME;
  
});
</script>

<input type="text" name="fNAME" placeholder="First Name">

Code Example 2

var express = require('express')
  var bodyParser = require('body-parser')
  var app = express()
  // parseapplication/x-www-form-urlencoded
  app.use(bodyParser.urlencoded({ extended: false }))
  // parse application/json
  app.use(bodyParser.json()) app.use(function (req, res) {  res.setHeader('Content-Type', 'text/plain')  res.write('you posted:\n')  res.end(JSON.stringify(req.body, null, 2))})

Code Example 3

$ npm install body-parser

Code Example 4

// Express/Connect top-level generic
// This example demonstrates adding a generic JSON and URL-encoded parser as a top-level middleware, which will parse the bodies of all incoming requests. 
// This is the simplest setup.

var express = require('express')
var bodyParser = require('body-parser') 
var app = express() 

// parse application/x-www-form-urlencoded
app.use(bodyParser.urlencoded({ extended: false })) 

// parse application/json
app.use(bodyParser.json()) 

app.use(function (req, res) {
  res.setHeader('Content-Type', 'text/plain')  
  res.write('you posted:\n')  
res.end(JSON.stringify(req.body, null, 2))})

Code Example 5

const jsonParser = bodyParser.json()

const urlencodedParser = bodyParser.urlencoded({ extended: false })

Code Example 6

var bodyParser = require('body-parser')

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