Two styles for setting defaults
<p>I have seen two different "styles" for setting a default value <code>default</code> to the variable <code>argument</code> in JavaScript:</p>

<pre><code>argument = argument || default     // Version 1
argument || (argument = default)   // Version 2
</code></pre>

<p>Are these completely equivalent? Is one faster than the other, or better in some other way?</p>
