How to test if given variable contains a valid html element?

Question

That is such with tag name and attributes so then I can safely use for example hasAttribute, tagName and other similar methods.

(My question is for a method of positively asking for html element, not for example ruling out all possibilities like string, number, some kind of other object etc.)

Answer 1

You check if it is an instance of HTMLElement

if (varName instanceof HTMLElement){
   // do what you want with the node
}