DOM: Node vs Element, NodeList vs HTMLCollection

• DOM: Difference Between NodeList, HTMLCollection

Iterable Object

NodeList and HTMLCollection are Iterable Objects. You can use for-of Loop on them.

Array-Like Object

NodeList and HTMLCollection are Array-Like Objects. [see Apply Array Method to Array-Like Object]

is Live Object?

• NodeList and HTMLCollection may or may not, be Live Object. e.g. document.querySelectorAll return a non-live NodeList.
• There's no builtin way to find out whether NodeList or HTMLCollection is live object.

What Does getElementsByClassName Return?

• DOM: History of GetElementsByClassName

How to Determine NodeList or HTMLCollection

You can find out the type by:

let xx = document.getElementsByClassName("xx");
Reflect.apply(Object.prototype.toString, xx, []);

It'll return a string like "[object HTMLCollection]" or "[object NodeList]".

[see Determine Type of Object]