javascript innerHTML adding instead of replacing

Answer 1

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.

Answer 2

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

Answer 3

What jcomeau_ictx suggested is an inefficient way of editing the innerHTML. Check Ben cherry's PPT http://www.bcherry.net/talks/js-better-faster

The correct way will be detaching the element and making changes to it and then appending it back to the parent node. Use https://gist.github.com/cowboy/938767 Native javascript from this gist to detach element.

Answer 4

Notice that using element.innerHTML += 'content' would empty inputs and textareas to their default, blank state, unclick checkboxes, as well as removing any events attached to those elements (such as onclick, on hover etc.) because the whole innerHTML would be reinterpreted by the browser, which means .innerHTML is emptied and filled again from scratch with the combined content.

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'
document.getElementById('oldElement').appendChild(newElement)

Answer 5

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

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

Answer 6

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