What's the difference between double exclamation operator and Boolean() in JavaScript?
<p>I know that <code>!!variable</code> will convert variable into a boolean value and the function <code>Boolean()</code>, according to the ecma262 spec, will also perform a type conversion by calling <code>ToBoolean(value)</code>.</p>

<p>My question is: what's the difference? Is <code>!!</code> better in performance than Boolean() ?</p>
