Javascript Add/Remove Class from selector

addClass.js

function addClass(selector, newClass) {

  // get all elements that match our selector
  elements = document.querySelectorAll(selector);

  // add class to all chosen elements
  for (var i=0; i<elements.length; i++) {
    elements[i].classList.add(newClass);
  }
}

// usage examples:
addClass('.class-selector', 'new-example-class');
addClass('#id-selector', 'new-example-class');

removeClass.js

function removeClass(selector, removingClass) {

  // get all elements that match our selector
  elements = document.querySelectorAll(selector);

  // remove class from all chosen elements
  for (var i=0; i<elements.length; i++) {
    elements[i].classList.remove(removingClass);
  }
}

// usage examples:
removeClass('.class-selector', 'removing-example-class');
removeClass('#id-selector', 'removing-example-class');