code: function transObjectAttrIntoArray(obj) {
    var fn = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : function (a, b) {
      return +a - +b;
    };
  
    return _Object$keys(obj).sort(fn).reduce(function (order, key) {
      return order.concat(obj[key]);
    }, []);
  }
docs: sort Object attributes by function
  and transfer them into array
  @param  {Object} obj Object form from numric
  @param  {Function} fn sort function
  @return {Array} the sorted attirbutes array