Please what can be the problems my code it keeps giving me can't set property of 'className' null

Question

https://code.sololearn.com/WB98QIcB1x3A/?ref=app

Henry Chigozie wave rider Michael Ngwerume Yeva

Answer 1

Do not use foul language as webpage title!

Reason: You try to access the DOM before it exists.

window.onload is the listener to ensure the scripts are executed after DOM exists.

A short cure for your current version :

window.onload = function() {
test();
}

Demo for full understanding :
https://code.sololearn.com/WriFNOoR188j/?ref=app

Answer 2

Also, replace div "holder" with div id="holder".

Answer 3

Henry Chigozie Uvaish Zafri wave rider