Prototype Chain and Inheritance - Node.js Object

Node.js examples for Object:Prototype

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Description

Prototype Chain and Inheritance

Demo Code


var Person = (function() {
  function Person (name, age) {
    this._name = name;/*from   w w w  . j  a v a 2  s.c  o m*/
    this._age = age;
  }

  Person.prototype.birthDay = function() {
    this._age += 1;
  };

  Person.prototype.getAge = function() {
    return this._age;
  }

  Person.prototype.setAge = function(newAge) {
    if (newAge <= 0) {
      return 'The age should be positive!';
    }
    this._age = newAge;
  }

  Person.prototype.toString = function() {
    return 'Name: ' + this._name + '\n' + 'Age: ' + this._age;
  };

  return Person;
}());


var Student = (function() {
  
  function Student (name, age, grade) {
    Person.call(this, name, age);    //vikame roditelskiq konstructor
    this._grade = grade;
  }

  Student.prototype = new Person();          // po tozi nacin Student nasledqva Person klasa
  Student.prototype.constructor = Student;  // ne zaduljitelen red, slagame go za da vurvi navsqkyde

  Student.prototype.toString = function() {
    return Person.prototype.toString.call(this) + //vikame toString metoda v bazoviq klas
    '\n' + 'Grade: ' + this._grade;
  };

  return Student;
}());


var st = new Person('Stanka', 22);
var st1 = new Student('Pesho', 16, 10);
console.log(st1.toString());
console.log(st.toString());



Object.prototype.extend = function (parent) {       // moje da se polzva vmesto Student.prototype = new Person();
  Student.prototype.constructor = Student;         // 
    if (!Object.create) {
        Object.prototype.create = function (proto) {
            function F() {
            };
            F.prototype = proto;
            return new F;
        };
    }

    this.prototype = Object.create(parent.prototype);
    this.prototype.constructor = this;
};

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