What's the best way to detect if a given Javascript object is a DOM Element?

Question

Say for instance I was writing a function that was designed to accept multiple argument types:

var overloaded = function (arg) {
 if (is_dom_element(arg)) {
  // Code for DOM Element argument...
 }
};

What's the best way to implement is_dom_element so that it works in a cross-browser, fairly accurate way?

Answer 1

typically you would check to see if the nodeName is defined on the object.

if(obj.nodeName){
    //Do Stuff here
}

Answer 2

Probably this one here:

node instanceof HTMLElement

That should work in most browsers. Otherwise you have to duck-type it (eg. typeof x.nodeType != 'undefined')

Answer 3

jQuery checks the nodeType property. So you would have:

var overloaded = function (arg) {
    if (arg.nodeType) {
        // Code for DOM Element argument...
    }
};

Although this would detect all DOM objects, not just elements. If you want elements alone, that would be:

var overloaded = function (arg) {
    if (arg.nodeType && arg.nodeType == 1) {
        // Code for DOM Element argument...
    }
};

Answer 4

What about

obj instanceof HTMLElement