createInnerProperty.js

function changeVal (obj, path, val) {
  var arr = path.split('.');
  var object = obj || {};
  var tempObj = object;
  
  for (var i = 0; i < arr.length - 1; i += 1) {
    if(typeof tempObj[arr[i]] !== 'object') {
      tempObj[arr[i]] = {};
    }
    tempObj = tempObj[arr[i]];
  }
  tempObj[arr[i]] = val;

  return object;
}