querySelector returns undefined string when trying to access numeric value as the ID of an element

Question

querySelector() returns undefined string when trying to access numeric value as the ID of an element. I would like to use querySelector() method over others, because it is more flexible. Any solutions to this problem would be a great help.

var foo = document.querySelector('#1');
console.log(foo);

jsFiddle

Answer 1

Weird .. Anyway this: document.querySelector('[id="1"]') is working. Fiddle: http://jsfiddle.net/wnd7K/2/

Answer 2

Renaming the ids of the elements so that they begin with a letter solves your problem e.g. : <div id="a1"></div>