Why this JavaScript code doesn't work

Question

I think i do the correct way, but what wrong on my code
https://code.sololearn.com/WPkIw8WMTmra/?ref=app

Answer 1

EsaKurniawan

Because className returns node list. Since there is only one element with that class so it should be like this:

document.getElementsByClassName("whatever")[0].innerHTML = "Why it's doesn't work";

But don't forget to write js code inside this function:

window.onload = function () {

}

------

window.onload = function () {
document.getElementsByClassName("whatever")[0].innerHTML = "Why it's doesn't work";
}

Answer 2

A͢J - S͟o͟l͟o͟H͟e͟l͟p͟e͟r͟ thanks it's work now