Answers for "add a class to body javascript"

add classnames to body

openModal = (event) => {
  document.body.classList.add('modal-open');
  this.setState({ showModal: true });
}
hideModal = (event) => {
  document.body.classList.remove('modal-open');
  this.setState({ showModal: false });
}

How to add a class to html element js

element.classList.add("my-class");