var getElementsByClassName = function (cName) {
  var obj = {};
  var count = 0;
  var allNodes = document.body.childNodes;
  // look inside body root for any element has className
  // if the className found, go over all child element
  for (var i = 0; i < allNodes.length; i++) {
    if (allNodes[i].nodeType === 1) {
      if (allNodes[i].classList == cName) {
        obj[count] = allNodes[i];
        count++;
        //return obj[count];
      }
    }
  }
  console.log(obj);
};

getElementsByClassName("example color");