object.ID = object.ID + 1;
object["ID"] = object["ID"] + 1;
object.grade.math = 100;
// Method can be called in the same way
object.sum(1, 2);

// Create new properties or methods in the same way
object[name + "-full"] = "Tom Hanks";
object.minus = function(a,b) {
  return a-b;
};