Why does var combined = null + "" has a value?
<p>Probably a very basic question from a confused javascript noob...</p>

<p>Why do</p>

<pre><code>var hasthisvalue = null;
if (hasthisvalue)
    print("hasthisvalue hs value");
</code></pre>

<p>and</p>

<pre><code>var hasthatvalue = "";
if (hasthatvalue)
    print("hasthatvalue has value");
</code></pre>

<p>don't print anything, but if I combine these two</p>

<pre><code>var combined = "hasthisvalue" + "hasthatvalue";
if (combined)
    print ("combined has value");
</code></pre>

<p>it does?</p>

<p>Or more directly:</p>

<pre><code>var combined = null + "";
if (combined)
    print ("combined has value");
</code></pre>

<p>Why does "combined" has a value if I only add two variables that don't have values? What am I missing?</p>
