How to get a URL parameter in Express?

Question

I am facing an issue on getting the value of tagid from my URL: localhost:8888/p?tagid=1234.

Help me out to correct my controller code. I am not able to get the tagid value.

My code is as follows:

app.js:

var express = require('express'),   http = require('http'),   path = require('path'); var app = express(); var controller = require('./controller')({   app: app });  // all environments app.configure(function() {   app.set('port', process.env.PORT || 8888);   app.use(express.json());   app.use(express.urlencoded());   app.use(express.methodOverride());   app.use(app.router);   app.use(express.static(path.join(__dirname, 'public')));   app.set('view engine', 'jade');   app.set('views', __dirname + '/views');   app.use(app.router);   app.get('/', function(req, res) {     res.render('index');   }); }); http.createServer(app).listen(app.get('port'), function() {   console.log('Express server listening on port ' + app.get('port')); }); 

Controller/index.js:

function controller(params) {   var app = params.app;   //var query_string = request.query.query_string;    app.get('/p?tagId=/', function(request, response) {     // userId is a parameter in the url request     response.writeHead(200); // return 200 HTTP OK status     response.end('You are looking for tagId' + request.route.query.tagId);   }); }  module.exports = controller; 

routes/index.js:

require('./controllers'); /*  * GET home page.  */  exports.index = function(req, res) {   res.render('index', {     title: 'Express'   }); }; 

Answer 1

Express 4.x

To get a URL parameter's value, use req.params

app.get('/p/:tagId', function(req, res) {   res.send("tagId is set to " + req.params.tagId); });  // GET /p/5 // tagId is set to 5 

If you want to get a query parameter ?tagId=5, then use req.query

app.get('/p', function(req, res) {   res.send("tagId is set to " + req.query.tagId); });  // GET /p?tagId=5 // tagId is set to 5 

---

Express 3.x

URL parameter

app.get('/p/:tagId', function(req, res) {   res.send("tagId is set to " + req.param("tagId")); });  // GET /p/5 // tagId is set to 5 

Query parameter

app.get('/p', function(req, res) {   res.send("tagId is set to " + req.query("tagId")); });  // GET /p?tagId=5 // tagId is set to 5 

Answer 2

You can do something like req.param('tagId')