Question

I wish to check if an argument passed to my function is an HTMLElement, using the instanceof operator. I know that this doesn’t work in IE7, because AFAIK IE7 doesn’t define HTMLElement. I figured: no problem, I’ll just fall back to a parent prototype like Node. But, as answers on StackOverflow have learned me, the Node-object is also not defined in IE7

What now is the best way to test if my parameter is a node/HTMLElement? Am I doing it wrong?

Answer 1

In the Node interface HTMLElement corresponds to nodes of type 1.

const unsigned short      ELEMENT_NODE                   = 1;

http://www.w3.org/TR/DOM-Level-2-Core/core.html#ID-1841493061

Thus, you should check for the argument’s nodeType:

if (arg && 1 === arg.nodeType) { /* ... */ }