javascript add css to a class code example

Example 1: js add class

// getting the target element
var myElement = document.querySelector('#myElement');

// example for addding some-class to the element
myElement.classList.add('some-class');

// multiple classes can be added like this
myElement.classList.add('one-class', 'one-more-class');

// example for removing any class from the element
myElement.classList.remove('any-class');

Example 2: js add style to each class

var all = document.getElementsByClassName('someClass');
for (var i = 0; i < all.length; i++) {
  all[i].style.color = 'red';
}