javascript - Finding DOM node index

Question

I want find the index of a given DOM node. It's like the inverse of doing

document.getElementById('id_of_element').childNodes[K]

I want to instead extract the value of K given that I already have the reference to the child node and the parent node. How do I do this?

Answer 1

The shortest possible way, without any frameworks, in all versions of Safari, FireFox, Chrome and IE >= 9:

var i = Array.prototype.indexOf.call(e.childNodes, someChildEl);