Set to empty string not removed id attribute.

<script type = "text/javascript">

 var el = document.createElement("div");

　alert(el.getAttribute("id"));
 alert(el.id);
 alert(el.hasAttribute("id")); // false

 el.id = "test";

 alert(el.getAttribute("id"));
 alert(el.id);
 alert(el.hasAttribute("id")); // true

 el.id = "";

 alert(el.getAttribute("id"));
 alert(el.id);
 alert(el.hasAttribute("id")); // true

</script>

But this looks strange:
"Either when an element is created that has an id attribute whose value is not the empty string or when an element's id attribute is set to a value other than the empty string, set the element's ID to the new value."

<script type = "text/javascript">

 var el = document.createElement("div");

　alert(el.getAttribute("id"));
 alert(el.id);
 alert(el.hasAttribute("id")); // false

 el.id = "";
 el.setAttribute("id", "");

 alert(el.getAttribute("id"));
 alert(el.id);
 alert(el.hasAttribute("id")); // true

</script>

Or maybe create/remove has some other meaning?

And another case:

<p id=""></p>

<script type = "text/javascript">

 alert(document.getElementById("")); // null

 var el = document.getElementsByTagName("p")[0];

　alert(el.getAttribute("id"));
 alert(el.id);
 alert(el.hasAttribute("id")); // true

</script>

https://github.com/whatwg/dom/commit/967552c81e1912a6ace72050a3a68a257c1ff672

spiritRKS1910 it seems you confuse the attribute with the "ID" concept. <p id=""> has an "id" attribute but does not have an ID.

Yup, I realize about it after submit this examples, but thx for answer, good catch.