Answers for "class name add 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 });
}

javascript add class to element

const element = document.querySelector('CSS_SELECTOR')

element.classList.add('class-1') // add class-1
element.classList.remove('class-1') // remove class-1
element.classList.toggle('class-1') // add class-1 if the element does not contains the class, remove if not.

JS DOM how to add a class name to any HTML element

var element = document.querySelector('.box');
// using add method
// adding single class
element.classList.add('color');

// adding multiple class
element.classList.add('border', 'shadow');