title: What reason is there to use null instead of undefined in JavaScript?
body: <p>I've been writing JavaScript for quite a long time now, and I have never had a reason to use <code>null</code>. It seems that <code>undefined</code> is always preferable and serves the same purpose programmatically. What are some practical reasons to use <code>null</code> instead of <code>undefined</code>?</p>