Whats the best way to find out if an Object is an Array
<p>As far as I know there are three ways of finding out if an object is an Array</p>

<p>by <code>isArray</code> function if implemented</p>

<pre><code>Array.isArray()
</code></pre>

<p>by <code>toString</code></p>

<pre><code>Object.prototype.toString.apply( obj ) === "[object Array]"
</code></pre>

<p>and by <code>instanceof</code></p>

<pre><code>obj instanceof Array
</code></pre>

<p>Is there any reason to choose one over the other?</p>
