javascript - Express error - TypeError: Router.use() requires middleware function but got a Object -

i getting error when run npm start run express app.

typeerror: router.use() requires middleware function got object

my app.js code

var express = require('express'); var path = require('path'); var favicon = require('serve-favicon'); var logger = require('morgan'); var cookieparser = require('cookie-parser'); var bodyparser = require('body-parser');  var routes = require('./routes/index'); var users = require('./routes/users');  var app = express();  // view engine setup app.set('views', path.join(__dirname, 'views')); app.set('view engine', 'ejs');  // uncomment after placing favicon in /public //app.use(favicon(__dirname + '/public/favicon.ico')); app.use(logger('dev')); app.use(bodyparser.json()); app.use(bodyparser.urlencoded({ extended: true })); app.use(cookieparser()); app.use(express.static(path.join(__dirname, 'public')));  app.use('/', routes); app.use('/users', users);    /// catch 404 , forwarding error handler app.use(function(req, res, next) {     var err = new error('not found');     err.status = 404;     next(err); });  /// error handlers  // development error handler // print stacktrace if (app.get('env') === 'development') {     app.use(function(err, req, res, next) {         res.status(err.status || 500);         res.render('error', {             message: err.message,             error: err         });     }); }  // production error handler // no stacktraces leaked user app.use(function(err, req, res, next) {     res.status(err.status || 500);     res.render('error', {         message: err.message,         error: {}     }); });  module.exports = app; 

my index.js code

var express = require('express'); var router = express.router();  /* home page. */ router.get('/', function(req, res) {     res.render('index', { title: 'express' }); });  /* hello world page. */ router.get('/helloworld', function(req, res) {     res.render('helloworld', { title: 'hello, world!' }) });  module.exports = router; 

i quirte new using node , express. cant see have gone wrong. can see problem is?

i found answer in comments kop4lyf:

check users.js. should exporting router index.js, if can try that.

however, question top search result when ran issue, promoting answer.

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the error caused because 1 of route modules not being exported - meaning express not have access when tries identify of routes.

you can fix adding module.exports = router; end of each of route files.

example:

var express = require('express'); var router = express.router();  router.get('/', function(req, res, next) {      //do whatever... });  module.exports = router; 

more information module.exports can found on this question or offcial node.js documentation.