appendchild javascript

function createMenuItem(name) {
    let li = document.createElement('li');
    li.textContent = name;
    return li;
}
// get the ul#menu
const menu = document.querySelector('#menu');
// add menu item
menu.appendChild(createMenuItem('Home'));
menu.appendChild(createMenuItem('Services'));
menu.appendChild(createMenuItem('About Us'));

const parent = document.createElement('div');
const child = document.createElement('p');
const childTwo = document.createElement('p');
parent.append(child, childTwo, 'Hello world'); // Works fine
parent.appendChild(child, childTwo, 'Hello world');
// Works fine, but adds the first element and ignores the rest

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

const parent = document.createElement('div');
const child = document.createElement('p');
const appendValue = parent.append(child);
console.log(appendValue) // undefined
const appendChildValue = parent.appendChild(child);
console.log(appendChildValue) // <p><p>

node.appendChild(node)