how to add text in html using javascript code example

Example 1: how add text to element in javascript

var paragraph = document.getElementById("p");
var text = document.createTextNode("This just got added");

paragraph.appendChild(text);

Example 2: how add text to element in javascript

var p = document.getElementById("p")
p.innerText = p.innerText+" And this is addon."

Example 3: how to add text in javascript

<div id="mass">
<p id="ph1">This is a paragraph.</p>
<p id="ph2">This is another paragraph.</p>
</div>

<script>
var head = document.createElement("h1");
var node = document.createTextNode("New Heading.");
head.appendChild(node);

var ele = document.getElementById("mass");
var child = document.getElementById("ph1");
ele.insertBefore(head,child);
//ele.append(head,child);

Output : 
New Heading.
This is a paragraph.
This is another paragraph.