why req.body is undefined code example

Example 1: req.body is undefined

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())

Example 2: express post request body undefined

/* USE:

npm i body-parser
*/

// then in your app
var express = require('express')
var bodyParser = require('body-parser')
 
var app = express()
 
// create application/json parser
var jsonParser = bodyParser.json()
 
// create application/x-www-form-urlencoded parser
var urlencodedParser = bodyParser.urlencoded({ extended: false })
 
// POST /login gets urlencoded bodies
app.post('/login', urlencodedParser, function (req, res) {
  res.send('welcome, ' + req.body.username)
})
 
// POST /api/users gets JSON bodies
app.post('/api/users', jsonParser, function (req, res) {
  // create user in req.body
})