Node.js ExpressJs Create Session

How can I create session in expressjs(4.0)?

I am doing exactly same in the links

var session = require('express-session');

/* session */
app.use(session({ secret: '1s2sd25asd7asd5asd7f4f1f'}))

However it gives error?

TypeError: Cannot read property 'connect.sid' of undefined

How do I create session in expressjs? I have been trying to create session for 3 days.

In express 4, create session like this

var express = require('express');
var app = express();
var cookieParser = require('cookie-parser');
var session = require('express-session');

You have to must use cookieParser before session

app.use(cookieParser())
app.use(session({secret: 'MySecret'}));

for further information, read connect official documentation here

Complete code :

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

app.set('views', __dirname + '/views');
app.engine('html', require('ejs').renderFile);

app.use(session({secret: 'ssshhhhh'}));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({extended: true}));

var sess;

app.get('/',function(req,res){
sess=req.session;
//Session set when user Request our app via URL
if(sess.email)
{
/*
* This line check Session existence.
* If it existed will do some action.
*/
res.redirect('/admin');
}
else{
res.render('index.html');
}
});

app.post('/login',function(req,res){
sess=req.session;
//In this we are assigning email to sess.email variable.
//email comes from HTML page.
sess.email=req.body.email;
res.end('done');
});

app.get('/admin',function(req,res){
sess=req.session;
if(sess.email)
{
res.write('
<h1>Hello '+sess.email+'</h1>
');
res.end('<a href="+">Logout</a>');
}
else
{
res.write('
<h1>Please login first.</h1>
');
res.end('<a href="+">Login</a>');
}

});

app.get('/logout',function(req,res){

req.session.destroy(function(err){
if(err){
console.log(err);
}
else
{
res.redirect('/');
}
});

});
app.listen(3000,function(){
console.log("App Started on PORT 3000");
});

Read here : http://codeforgeek.com/2014/09/manage-session-using-node-js-express-4/