title: Node.js fs.readFile store read data in memory
body: <p>I'm building a node.js app which will process a lot of numerical data.
  How do I store in memory data which has been read by fs.readFile, Example:</p>
  <pre><code>var somedata = ''; 
  fs.readFile('somefile', 'utf8', function(err,data){
   somedata = data; 
  });
  
  //fs.readFile is done by now.. 
  console.log(somedata) // undefined, why is this not in memory? 
  </code></pre>
  <p>I read file data periodically and currently I have to write what ive read elsewhere and read it again to use it in another function.</p>
  <p>How do i just store it in memory? Is this just how javascript works??</p>