Can we cast a generic object to a custom object type in javascript?

Question

For example, I already have this object somewhere in the code, it is a generic object:

var person1={lastName:\"Freeman\",firstName:\"Gordon\"};

Answer 1

No.

But if you're looking to treat your person1 object as if it were a Person, you can call methods on Person's prototype on person1 with call:

Person.prototype.getFullNamePublic = function(){
    return this.lastName + ' ' + this.firstName;
}
Person.prototype.getFullNamePublic.call(person1);

Though this obviously won't work for privileged methods created inside of the Person constructor—like your getFullName method.