Object Oriented Programing in JavaScript

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Ad

Object Oriented Programing
in
Akshay Mathur

Akshay Mathur
• Founding Team Member of
– ShopSocially (Enabling “social” for retailers)
– AirTight Neworks (Global leader...

JS Objects

Objects
• Everything in JS is an object (instance)
“string”.length // 6
“str”.length.toFixed(2) // “3.00”
[„hell‟, „o!‟].j...

Custom Objects
• JavaScript Object has a key and a value
• Key is always string
• Value can be of any type
– Including ano...

Object as Namespace
• It is a good practice to group variables and
functions together in an object rather than
keeping the...

Object as Named Argument
• Objects can be passed to a function as an argument
• They proxy for named arguments
Say_hello =...

@akshaymathu 8

JS Functions

$Function • Code block that executes on ‘call’ //define the function function say_hello(name){ alert(„Hello! „ + name); } /...$

Function Arguments
• Any number of arguments can be passed without
declaring
• Named arguments are not supported
say_hello...

$Naming a Function function my_func(){} • A function may not have a name function(){}; my_func = function(){}; @akshaymathu...$

Variable Scope
• By default all variables are global
• Variables defined with ‘var’ keyword are local to
the function
• It...

Return Values
• Anything can be returned from a function
using return statement
function sqr(x){
var sq = x * x;
return sq...

Other Facts
• A function can be assigned to a variable
• A function can be defined within another function
• A function ca...

16@akshaymathu

JavaScript Classes

Class
• Class is a reserved keyword in JS
– But not implemented
– Same effect is achieved via prototype
• CofeeScript allo...

Using Functions as Objects
• Functions are actually First Class objects
So we can change
User= {}
User.name = „Akshay‟
Use...

Creating Instances
• Now the object instance can be created using
new keyword
user1 = new User; user1.name
//Akshay user1....

Object Constructor
• The main object function can take arguments for
initializing properties
User = function(name){
this.n...

Extending a Class
• More functions and properties can be defined
extending the prototype of the class
User.prototype.setGe...

Further Reading
• Introduction to Object-Oriented JavaScript on
Mozilla Developer Network
https://developer.mozilla.org/en...

Thanks
@akshaymathu 24@akshaymathu
http://www.quora.com/Akshay-Mathur