Person.fullname = function() {// Result: Person.prototype.fullname.call(this, joiner,..., argN); return Function.call.apply(Person.prototype.fullname, arguments);}; var grace = new Person("Grace", "Hopper"); // 'Grace Hopper' grace.fullname(); // 'Turing, Alan' Person.fullname({first: "Alan", last: "Turing"}, ", ", {order: "eastern"}); Formal Parameters and Arguments Indices The arguments object creates getter and setter functions for both its properties, as well as the function's formal parameters.