add text in tag in js code example

Example 1: how add text to element in javascript

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

Example 2: how add text to element in javascript

var h = document.createElement("H1")                // Create a <h1> element

 var t = document.createTextNode("Hello World");     // Create a text node

 h.appendChild(t);                                   // Append the text to <h1>