Question

I expect this to print “a” because when I call foo(this), the argument seems to be the link tag.

<script type="text/javascript">
    function foo (e) {
        alert (e .tagName);
    }
</script>
<a href="javascript:foo(this)">click</a>

Instead, it prints “undefined”. If I alert(e) it says “object Window”. How do I make foo know which element launched it? Without passing/looking up ids.

Answer 1

You should not use href for JavaScript. Bad practice, instead use onclick and this will magically point to the link.

<a href="#" onclick="foo(this)">click</a>

You also need to cancel the click action of the link. Either with return false or cancelling the event with preventDefault.

It is better to attach the event with Unobtrusive JavaScript