title: Is Node.js Array.map() asynchronous?
body: <p>Can I count on nodeIDs mapping is completed every time doSomething() is called?</p>
  
  <pre><code>nodeIDs = $.map(nodeIDs, function(n){
      return n.match(/\d+$/);
  });
  doSomething(nodeIDs);
  </code></pre>
  
  <p>I thought all callbacks in node.js are asynchronous?  I did read an article on general programming that callback could be synchronous but I am not sure about node.js? </p>