JS - Remove class from HTML elements

js-DOM-removeClass.js

/******************************************************************************************************
* @function removeClass
* @param (elements) - String selector (eg: '#iddiv' or '.classdiv') 
*                     or DOM elements (eg: document.querySelectorAll('.classdiv') )
* @param (myClass) - String calss name you whant to remove (eg: 'newClass')
******************************************************************************************************/
function removeClass(elements, myClass) {

  // if there are no elements, we're done
  if (!elements) { 
    return; 
  }
  
  // if the class name is not a string, throw an error
  if(typeof myClass !== 'string'){
    throw new Error(myClass + ' is not a string');
    return;
  }

  // if we have a selector, get the chosen elements
  if (typeof(elements) === 'string') {
    elements = document.querySelectorAll(elements);
  }
  else if (elements.tagName) { // if we have a single DOM element, make it an array to simplify behavior 
    elements=[elements]; 
  }

  // create pattern to find class name
  var reg = new RegExp('(^| )'+myClass+'($| )','g');

  // remove class from all chosen elements
  for (var i=0; i<elements.length; i++) {
    elements[i].className = elements[i].className.replace(reg,' ');
  }
}