Javascript Best Practices Presented by Ramkumar Murugadoss at Techday7 Chennai Meetup on Nov 24 2012

1. Javascript
DEVELOPER’S LIFE

2. Who am I?
• Ramkumar Murugadoss
• @rampicos
• facebook.com/raamkumar.m
• Code

3. What is JavaScript
• Javascript is the Programming language, first emerged to
make dynamic scripts for Web pages
• What do you think about Javascript?

4. Why Javascript
• What we use for: Programming Language for Web Pages
• How it was in current: Programming Language for Server-side too
• In near future: It is most wanted huge Programming Language for all

5. Best Practices
• All we know Javascript
• Everyone can code in Javascript
• All we want to know, how efficiently we will write JS

6. About GC
• GC is automatic
• Objects are collected there is no references longer
• Javascript Uses Mark and Sweep GC method

7. Avoid the global scope
• In the Global scope the Object never null, so never garbage
collected
• It’s time taking and trivial process to get the reference of
global scope
• If need to use global scope assign yourself null after the use

8. Use var
• Don’t forget to use var for all your variables
• The Variables without var may considered to global
• You are making javascript to struggle for finding the scope of
your variable

9. Get Use of Self-Calling Functions
• Have any one noticied jQuery using self calling functions

10. What will be the result?

11. Make your loops more efficient

12. Conditional Branching

13. Creating Arrays and Objects
• Use [] instead of Array
• Use arrayVariable[length] = value instead of
arrayVariable.push(value)
• Use {} instead of Object

14. Closures
• A closure is a special kind of object that combines two
things: a function, and the environment in which that function
was created
• The environment consists of any local variables that were in-
scope at the time that the closure was created

15. Closures Cond…

16. Closures Cond…

17. Namespaces
• this prevent the global scope pollution
• this protect your code from colliding with other code or libraries

18. Building String in Loops

19. Small Intro to OOPs
• Everything in Javascript is Object based, (note there is no keyword called class in
JS)
• Now the question is then how can I create the Objects and its functions?

20. OOPs cond
• Creating functions in JS is considered to the Object, using prototypes you can
define methods for that

21. Any Guess
• What is the difference between this two codes

22. Don’t D.R.Y
• Make the reusability
• Make use of Namespace

24. Cross Platform Mobile Applications
• What are Cross Platform Mobile Applications ?
• Why build Cross Platform ?
• What are the most popular development framework available ?
• Which framework should I use?

25. Why Titanium
• Code Once Build Everywhere
• Native look and feel
• Has more than 5,500+ device level APIs for iOS and Android
• Object based Javascript only
• In build Analytics
• In build Cloud integration support (ACS)
• Much more

26. What to do to start with Titanium today?
Signup and download http://my.appcelerator.com
Follow the “Quick Start” https://wiki.appcelerator.org/display/guides/home
You’re ready to be a Titanium developer!

27. CommonJS
• The Biggest feature introduced from Node.js for reusability is CommonJS
• Make your functions as unique namespaced modules and get to use of that
• We have exports.yourfunction and module.exports as 2 ways to create
CommonJS modules
• Woow now browsers support CommonJS with some libraries

28. exports.your function

29. module.exports