Nodejs - Level 0 Trying to understand the need for Nodejs and what it is. This will not teach you nodejs it will explain why nodejs.

1. NodeJs
Level 0

5. – undefined
“I/O needs to be done differently , we are doing it
wrong.”

6. Blocking I/O

9. So what if its blocked?
• Threads SUCK
• Memory ~512 Kb
• CPU - hence thread pools
• Latency

13. Non-Blocking I/O

14. CALLBACK
EXECUTED WHEN DATA IS READ
DOWN HERE DO SOME OTHER STUFF

15. Non-Blocking I/O
• All code runs on a single thread
• Functions listen to event
• They act on event and sleep
• All I/O has to be non blocking

16. Single Threaded
Asynchronous
Event - Driven
Platform Independent

19. +

20. Recap Event Loop

23. Let me tell you a
story…

24. Some years
ago…

27. NodeJs Facts
• Code in Javascript
• Powered by Google Chrome’s V8 engine
• Uses JSON as the data exchange format
• NodeJs community is open, any one can share code in
public repository
• Node Package Manager (NPM) is included in node by
default.

31. Create a project
$ npm init

33. package.json

34. index.js

35. Run
$ node index.js

36. Lets create a http
server

37. index.js
require() method is used to load the
module in your code

39. Install a module
$ npm install <module name>

40. Install express
$ npm install express

41. package.json

42. index.js
Express is a sweet layer over native http
server

45. “One thing more”

46. Create your own module

47. Require that module

49. Next Time