What is the purpose/benefit of using ignored parameters in a JavaScript function?
<p>Just so there is no misunderstanding, this question is not about allowing for optional parameters in a JS function. </p>

<p>My question is motiviated by the jQuery <code>parseXML</code> function, which is defined in <code>jQuery.js</code> as follows:</p>

<pre><code>// Cross-browser xml parsing
// (xml &amp; tmp used internally)
parseXML: function( data, xml, tmp ) { 
   ... 
} 
</code></pre>

<p>Within the body of the function, the parameters <code>xml</code> and and <code>tmp</code> are both assigned before they are used. That means they are being used as local variables, so the function could have been defined like this:</p>

<pre><code>parseXML: function(data) { 
   var xml, tmp;
   ... 
}
</code></pre>

<p>What is the benefit of doing it the first way, other than saving a few characters in the minified version of <code>jQuery.js</code>?</p>
