What does the syntax in this two expression for loop mean?
<p>What do the two expressions <code>var i = 0, item; item = a[i++];</code> mean?</p>

<pre><code>for (var i = 0, item; item = a[i++];) {  
    // Do something with item  
}  
</code></pre>

<p>Apparently this is an alternative to </p>

<pre><code>for (var i = 0; i &lt; a.length; i++) {  
    // Do something with a[i]  
}  
</code></pre>
