javascript innerHTML adding instead of replacing

quick question, i know we can change the content of a

<div id="whatEverId">hello one<div> by using:

document.getElementById("whatEverId").innerHTML="hello two";

now, is there a way I can ADD stuff to the div instead of replacing it??? so i can get

<div id="whatEverId">hello one hello two<div>

(using something similar of course)

<div id="whatever">hello one</div>
document.getElementById("whatever").innerHTML += " hello two";

document.getElementById("whatEverId").innerHTML =  document.getElementById("whatEverId").innerHTML +  "hello two" + document.getElementById("whatEverId").innerHTM ;

What jcomeau_ictx suggested is an inefficient way of editing the innerHTML. Check Ben cherry's PPT

The correct way will be detaching the element and making changes to it and then appending it back to the parent node. Use Native javascript from this gist to detach element.

Notice that using element.innerHTML += 'content' would empty inputs and textareas to their default, blank state, unclick checkboxes etc. because the whole innerHTML would be reinterpreted by the browser.

If you need to keep the state, you'd need to create a new element (a <span> for instance) and append it to the current element, as in:

let newElement = 'span'
newElement.innerHTML = 'new text'

If you are appending, you can just change your = to a +=

document.getElementById("whatEverId").innerHTML += 'hello two';

If prefixing

document.getElementById("whatEverId").innerHTML = 'hello two' + document.getElementById("whatEverId").innerHTML;

Although I would highly recommend using jQuery or MooTools javascript libraries/frameworks to do this sort of thing. If you're adding tags not just text nodes, then you should use the DOM createElement or one of the aforementioned libraries/frameworks.

You can do it by appending div string like this..

document.getElementById('div_id').innerHTML += 'Hello Two';