javascript - can't retrieve src attribute with document.getElementById -

good day, have small rpoblem can't retrieve src html attribute out of document.getelementbyid

<div id="1" src="great.png">  var = document.getelementbyid(1).src; document.write(a); 

gives nothing.

src non-understand attribute div tag. need use getattribute('src')

var = document.getelementbyid("1");  console.log( a.getattribute('src') );  console.log( a.src ); // undefined

<div id="1" src="great.png">

using img tag

var = document.getelementbyid("1");  console.log( a.getattribute('src') );  console.log( a.src );

<img id="1" src="great.png">