I dont understand this portion of js plz help

Question

https://code.sololearn.com/WrqU79uQYl3y/?ref=app

Answer 1

Its document.getElementById("ID")

Its HTML DOM(document object model) manipulation using Js

Basically 'var ID' creates a var and document.getElementById("hello") gets element with id 'hello' and assign it to var ID

Then you can change inner html of element with ID 'hello' by using
ID.innerHTML = "Hello"

You can learn more from here :
https://www.javascripttutorial.net/javascript-dom/

Or it's already in sololearn Js course

Answer 2

YuZu thanks