JavaScript private public privileged access

December 26, 2012

Public

The members of an object are all public members. There are two ways for putting members in a new object.

In Constructor

function Container(param) {
    this.member = param;
}

In the prototype

This technique is used to add public methods.

Container.prototype.stamp = function (string) {
    return this.member + string;
}

Private
Private members are made by the constructor. Ordinary vars and parameters of the constructor become the private members.

function Container(param) {
    this.member = param;
    var secret = 3;
    var that = this;
}

Privileged

A privileged method is able to access private methods, variables and is itself accessible to the public method and the outside.  Privileged methods are assigned with “this” within the constructor.

function Container(param) {
    this.member = param;

    this.service = function () {
        return this.member;
    };
}

 

http://javascript.crockford.com/private.html

http://phrogz.net/JS/classes/OOPinJS.html

https://developer.mozilla.org/en-US/docs/JavaScript/Guide/Inheritance_and_the_prototype_chain

https://developer.mozilla.org/en-US/docs/JavaScript/Introduction_to_Object-Oriented_JavaScript

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Object Oriented Programming

December 19, 2012

Object

Object is an instance of a class.  All objects have a state and behavior.

Class

Class is the blueprint from which individual objects are created

Inheritance

Object-oriented programming allows classes to inherit commonly used state and behavior from other classes. In Java programming language, each class is allowed to have one direct superclass, and each superclass has the potential for an unlimited number of subclasses.

Interface

Methods form the object’s interface with the outside world. An interface is a group of related methods with empty bodies.  Interface separates implementation and defines the structure. It is useful when the implementation changes frequently.  Interface forms a contract between the class and the outside world.

Abstract Class

Abstract classes cannot be instantiated.  It can only be used as a super class for other classes that extend the abstract class.  Abstract classes are declared with keyword abstract.  Abstract class methods can have implementations. Abstract class’s methods can’t have implementation only when declared abstract.

Encapsulation

Encapsulation is inclusion within a program object of all the resources needed for the object to function.  It allows class to change its internal implementation without hurting the overall functioning of the system.

Polymorphism

Polymorphism is the ability to request that the same operations be performed by a wide range of different types of things.

Method overloading

Ability to define several methods all with the same name

Method overridding

Subclass overrides a specific implementation of a method that is already provided by one of its super classes.

References

http://docs.oracle.com/javase/tutorial/java/concepts/object.html

http://www.codeproject.com/Articles/22769/Introduction-to-Object-Oriented-Programming-Concep#OOP