Attach prototype to JavaScript object

Question

Let's say I have the following JSON with person objects.

[
  {
     "name": "Alice",
     "age": 28,
  },
  {
     "name": "Bob",
     "age": 33
  }
]

If I parse this, I will get an array with two JavaScript objects. Let's say, I want to equip these two objects with a method called introduce, that does something like this

function introduce() {
  return "My name is " + this.name + " and I am " + this.age + " years old.";
}

Now, I could iterate over my two people and call

person.constructor.prototype.introduce = introduce

However, this will expose the introduce function in ALL JavaScript objects, not just the two above.

I could also manually attach the function to each object, but if I want to extend my people with additional functions, I will have to iterate over all people again.

Ideally, I would like a prototype that I can fit with the introduce method and then attach this prototype to all my people, so if I later extend the prototype, my people will gain additional functions as well.

The question is: how?

Answer 1

I suggest you to create a class:

JSBin

var Person = (function () {
    function Person(person) {
        this.person = person;
        this.name = person.name;
        this.age = person.age;
    }
    Person.prototype.introduce = function () {
        return "My name is " + this.name + " and I am " + this.age + " years old.";
    };
    return Person;
})();

Answer 2

You're question is a little fuzzy to understand. But I think you don't want your "person" to be a regular object, but rather a separate person "class:"

var Person = function(obj){
    this.name = obj.name;
};

Person.prototype.introduce = function(){
  return console.log('hi, I\'m '+this.name);
};

var personA = new Person({ name:'a' });
var personB = new Person({ name:'b' });

personA.introduce();  // "hi, I'm a"
personB.introduce();  // "hi, I'm b"