What's the purpose of javascript parameters that are overwritten in the function?
<p>I have a code snippet to include in a project, and I'd like to know if there's a purpose to why it was written like this or if I should clean it up.  Is there an optimization trick I don't know about?</p>

<p>Here's the (sanitized) code snippet.  Notice a,b,c,d passed in and then assigned in the function.</p>

<pre><code>(function (a, b, c, d) {
    a = '//url/to/js/file.js';
    b = document; c = 'script'; d = b.createElement(c); d.src = a; d.type = 'text/java' + c; d.async = true;
    a = b.getElementsByTagName(c)[0]; a.parentNode.insertBefore(d, a);
})();
</code></pre>

<p>I found <a href="http://stackoverflow.com/questions/5519701/what-is-the-purpose-benefit-of-using-ignored-parameters-in-a-javascript-function">this answer</a> after writing this question up.  Is that the only reason?</p>
