express thows error as 'cannot call method set`

Question

express thows error as 'cannot call method set`

I'm starting a node app like this:

var express = require('express');
var jade = require('jade');


app.set('view engine', 'jade');


var app = express();
var env = process.env.PORT || 3000;


app.listen(env, function(req, res){
    console.log('i am working!');
});

But I'm getting this error while I run my app...

D:\myLogin>node app

D:\myLogin\app.js:5
app.set('view engine', 'jade');
    ^
TypeError: Cannot call method 'set' of undefined
    at Object.<anonymous> (D:\myLogin\app.js:5:5)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Function.Module.runMain (module.js:497:10)
    at startup (node.js:119:16)
    at node.js:906:3

What is missing here?

node.js
express

Answer 1

In here :

app.set('view engine', 'jade');
var app = express();

you assign a value to app after you call a function on that value. So of course app is undefined when you do the set.