<!DOCTYPE html>
<html>
<head></head>
<body>
<p data-foo="0"></p>
<h6 data-foo="1"></h6>
<script>
var a = document.querySelectorAll('[data-foo]');
for (var i in a) if (a.hasOwnProperty(i)) {
alert(a[i].getAttribute('data-foo'));
}
</script>
</body>
</html>
document.querySelectorAll("[data-foo='1']")
//javascript get html data attributedocument.querySelectorAll("[data-foo]")