Check that value is object literal?

Question

I have a value and want to know if it\'s an iteratable object literal, before I iterate it.

How do I do that?

Answer 1

Strangely, I'm seeing different values for toString() for a subclassed object depending how toString() is being called:

Object.prototype.toString.call(aThing)
"[object Object]"

aThing.toString()
"ZmPopupMenu"

That results in a false positive, so I amended it to prefer the object's toString():

var str = someObject.toString
    ? someObject.toString()
    : Object.prototype.toString.call(someObject);
return str === '[object Object]';