title: Cannot find module 'socket.io' after global install
body: <p>I try to use socket io so I follow they tutorial in <a href="http://socket.io/get-started/chat/" rel="nofollow noreferrer">here</a>.
  I did:</p>
  
  <pre><code> var app = require('express')();
  </code></pre>
  
  <p>And I get this error:</p>
  
  <blockquote>
    <p>Error: Cannot find module 'express'</p>
  </blockquote>
  
  <p>Before running I did in the command line:</p>
  
  <pre><code>npm install --save express@4.10.2
  </code></pre>
  
  <p>Like described in they tutorial.
  So I search for that and I find this answer <a href="https://stackoverflow.com/questions/14949118/node-js-error-cannot-find-module-express">node.js, Error: Cannot find module &#39;express&#39;</a></p>
  
  <p>So I did like the first answer:</p>
  
  <pre><code> npm install express
  </code></pre>
  
  <p>And now I get this error:</p>
  
  <blockquote>
    <p>Error: Cannot find module 'socket.io'</p>
  </blockquote>
  
  <p>So I search again and I found that I need to install its globaly (<a href="https://stackoverflow.com/questions/17058298/error-cannot-find-module-socket-io">Error: Cannot find module &#39;socket.io&#39;</a> first answer)</p>
  
  <p>So I did:</p>
  
  <pre><code> npm install -g socket.io
  </code></pre>
  
  <p>But still the same error again.</p>
  
  <p>What should I do?</p>