JavaScript | hasClass, addClass, removeClass

checkClass.js

// Pure JavaScript hasClass, addClass, and removeClass.
// Source: http://www.avoid.org/?p=78
function hasClass(el, name) {
   return new RegExp('(\\s|^)'+name+'(\\s|$)').test(el.className);
}
function addClass(el, name) {
   if (!hasClass(el, name)) { el.className += (el.className ? ' ' : '') +name; }
}
function removeClass(el, name) {
   if (hasClass(el, name)) {
      el.className=el.className.replace(new RegExp('(\\s|^)'+name+'(\\s|$)'),' ').replace(/^\s+|\s+$/g, '');
   }
}