Prototype inheritance example

main.js

/**
 * Super class constructor.
 */

function Animal() {
  this.type = 'animal';
}

/**
 * Set `Animal` prototype methods.
 */

!function(proto) {
  
  /**
   * Define private method.
   */
  
  function pseudoPrivateFn() {
    console.log('name: %s', this.name);
  }
  
  /**
   * Define public method.
   */
  
  proto.superPublicFn = function() {
    console.log('I am superPublicFn.');
    pseudoPrivateFn.call(this);
  };
  
}(Animal.prototype);

/**
 * Subclass constructor.
 */

function Human() {
  Animal.apply(this, arguments);
  
  this.name = 'John Doe';
}

/**
 * Inherits from `Animal`
 */

Human.prototype = new Animal();

/**
 * Set `Human` prototype methods.
 */

!function(proto) {

  /**
   * Define private method.
   */
  
  function pseudoPrivateFn1() {
    console.log(Object.prototype.toString.call(this));
    console.log("type: %s", this.type);
  }
  
  /**
   * Define private method.
   */
  
  function pseudoPrivateFn2() {
    console.log("name: %s", this.name);
    console.log("age: %s", this.age);
    console.log("protoValue: %s", proto.protoValue);
  }
  
  /**
   * Define public method.
   */
  
  proto.subPublicFn1 = function() {
    console.log("I am subPublicFn1,");
    pseudoPrivateFn1();
    pseudoPrivateFn1.call(this);
  };
  
  /**
   * Define public method.
   */
  
  proto.subPublicFn2 = function() {
    console.log("I am subPublicFn2.");
    pseudoPrivateFn2();
    console.log("My name is %s!", this.name);
    pseudoPrivateFn2.call(this);
  };
  
  proto.protoValue = 100;
  
}(Human.prototype);

/**
 * Usage.
 */

var human = new Human();
human.superPublicFn();
human.subPublicFn1();
human.subPublicFn2();
human.age = 25;
human.subPublicFn2();

stdout.txt

I am superPublicFn.
name: John Doe
I am subPublicFn1,
[object global]
type: undefined
[object Object]
type: animal
I am subPublicFn2.
name: undefined
age: undefined
protoValue: 100
My name is John Doe!
name: John Doe
age: undefined
protoValue: 100
I am subPublicFn2.
name: undefined
age: undefined
protoValue: 100
My name is John Doe!
name: John Doe
age: 25
protoValue: 100