Answers for "appendchild documentelement returns another html file"

appendchild javascript

const parent = document.createElement('div');
const child = document.createElement('p');
// Appending Node Objects
parent.append(child) // Works fine
parent.appendChild(child) // Works fine
// Appending DOMStrings
parent.append('Hello world') // Works fine
parent.appendChild('Hello world') // Throws error

how to appendChild in the begin of the div javascript

var element = document.getElementById("div1");
element.insertBefore(para, element.firstChild);