Since I didn't call any Array methods, I went with a simple typeof check.
I'll use `Array.isArray()` instead.

<blockquote>
Math.max returns -Infinity on empty list already.
</blockquote>

	Math.max() === -Infinity;
	
Agree. However, the goal is not use `Math.max.apply()` in order to avoid the `max call stack size` exception. 
Math.max isn't useful so I didn't use it.