Express app will not start with node app.js - node.js

Question

I was following along to this tutorial about setting up an express app. But when I ran node app.js the server would not start. The previous command that I ran was
cd express_example && npm install
But I got this error
npm WARN engine express#4.9.8: wanted: {"node":">= 0.10.0"} (current: {"node":"0.8.4","npm":"2.1.4"})
npm WARN engine void-elements#1.0.0: wanted: {"node":">=0.10.0"} (current: {"node":"0.8.4","npm":"2.1.4"})
So i thought that it was because a newer version of node was necessary. So I looked at the version of node that I had, noticed it was older so I tried upgrading. But when I ran brew update node i got this alert.
Error: node-0.10.32 already installed
I did some searching around and found this answer here on SO. Which suggested running these commands
sudo npm cache clean -f
then
sudo npm install -g n
then
sudo n stable
But the server still wont startup. But at least I am now at v0.10.33
I also found this similar question on SO whose accepted answer said to try sudo node app.js but that just does not seem right, nor did it even work.

Answer 1

If you are using Express 4 and using the generator, there is a slightly diffrent method for running the app. Express 4 changed the file structure to:
├── app.js
├── bin
│ └── www
├── package.json
├── public
│ ├── images
│ ├── javascripts
│ └── stylesheets
│ └── style.css
├── routes
│ ├── index.js
│ └── users.js
└── views
├── error.jade
├── index.jade
└── layout.jade
Notice the bin/www directory.
The app start logic is now seperated in the bin/www file. Therefore you have to run your app with the following command:
DEBUG=<<app_name>> ./bin/www
Reference: http://expressjs.com/starter/generator.html