We used the document.getElementsByClassName() method to get an HTMLCollection of the elements with the specific class

const elements = document.getElementsByClassName('someClass');

  for (let element of elements) {

    element.style.display = 'none';

    // another way
    element.style.visibility = 'hidden';
  }

const elements = document.getElementsByClassName('someClass');

  for (let element of elements) {

    element.style.display = 'block';

    // another way
    element.style.visibility = 'hidden';
  }