Finding a DOM node in the subtree of a node?

I have HTML with something like

<div class="foo">
<h1>foo 1</h1>
..</div>

<div class="foo">
<h1>foo 2</h1>
..</div>

Finding the div nodes using getElementsByTagName('开发者_开发问答div') is not a problem.

While iterating of the div nodes I need to find the first H1 inside the subtree of the DIV nodes. Is there something like getElementByTagName() on a DOM node?

No. Use array notation to get the first element found:

var firstHeading = div.getElementsByTagName('h1')[0];

Edit If you were asking if you could use getElementsByTagName on nodes other than the document, yes you can. All DOM element nodes plus the document node have the getElementsByTagName method.