var Obj = function Obj(name, surname, age) {
this.name = name,
this.surname = surname,
this.age = age
}
var obj1 = new Obj('Józek', 'Kowalski', 19);
obj1.constructor //wskazuje na function Obj
var obj2 = new obj1.constructor('Marcin', 'Dziędziel', 34);