Add a class to body

Question

How can I add a class to the body in ES6 JS?

I've tried:

let body = document.getElementsByTagName('body');
body.classList.add('my-class');

It fails. No Jquery please.

Possible duplicate of [What do querySelectorAll, getElementsByClassName and other getElementsBy\* methods return?](http://stackoverflow.com/questions/10693845/what-do-queryselectorall-getelementsbyclassname-and-other-getelementsby-method) — Sebastian Simon, Mar 20 '17 at 15:34
Use `document.body` instead of `document.getElementsByTagName('body')`. `getElementsByTagName` returns an `HTMLCollection`. They don’t have `classList`s. The console should’ve told you already. — Sebastian Simon, Mar 20 '17 at 15:34
also a minor thing, if you don't intend to change the variable value, consider using `const` instead of `let` — pwolaq, Mar 20 '17 at 15:58

score 1 · Answer 1 · answered Mar 20 '17 at 15:55

1

I think the problem for your code is document.getElementsByTagName('body') will return a HTMLCollection, you need to

let body = document.getElementsByTagName('body')[0];

answered Mar 20 '17 at 15:55

1 Answers1