how to insert html in javascript code example

Example 1: how to add elements in javascript html

//adding 'p' tag to body

  var tag = document.createElement("p"); // <p></p>
  var text = document.createTextNode("TEST TEXT"); 
  tag.appendChild(text); // <p>TEST TEXT</p>
  var element = document.getElementsByTagName("body")[0];
  element.appendChild(tag); // <body> <p>TEST TEXT</p> </body>

Example 2: Inserting HTML elements with JavaScript

function create(htmlStr) {
    var frag = document.createDocumentFragment(),
        temp = document.createElement('div');
    temp.innerHTML = htmlStr;
    while (temp.firstChild) {
        frag.appendChild(temp.firstChild);
    }
    return frag;
}

var fragment = create('<div>Hello!</div><p>...</p>');
// You can use native DOM methods to insert the fragment:
document.body.insertBefore(fragment, document.body.childNodes[0]);

Example 3: js create tag

//create div
let div = document.createElement('div');
//create button
let button = document.createElement('button');