Ruby Introduction

General introduction to language Ruby

Transcript

1. Ruby Introduction
2. print “Hello World” Hello World
3. Most things in Ruby is Object
4. OObject of class String OObject of class Fixnum
5. Conditionals or elsif admin == false paranthesis is optional
6. Methods No return type needed Paranthesis is optional Ruby method returns the last line Method is called
7. Loops
10. Arrays
11. Inserting into an Array
12. Deleting from an Array
13. Looping through an Array
14. Hash
15. KEY Value Based on key, you can get the value
16. Changing the value
17. Adding a new Key value pair
18. Symbols
19. How it differs from a String Saves memory and remains in memory always
20. Symbols can be used as keys in Hash
21. Class Constructor Method
22. Inheritance
23. ➢ Global - $ ➢ Instance - @ ➢ Class - @@ ➢ Local - [a-z] or _ ➢ Constants - CAPS Variables
24. Global Variables $myvar = “Its is a Place” class Chennai def what_is_that puts $myvar end end class NewYork def what_is_that puts $myvar end end Output: chennai = Chennai.new newyork = NewYork.new chennai.what_is_that newyork.what_is_that -------------------------------------- Its is a Place Its is a Place
25. Instance Variables class Place def initialize(place) @current_place = place end def show_me puts @current_place end end Output: chennai =Place.new(“Chennai”) newyork = Place.new(“New York”) chennai.show_me newyork.show_me -------------------------------------- Chennai New York
26. Class Variables @@hotels=0 class Place def more_hotels @@hotels +=1 end end Output: chennai =Place.new newyork = Place.new chennai.more_hotels newyork.more_hotels -------------------------------------- 1 2
27. Local Variables Output: chennai =Place.new(“Chennai”) newyork = Place.new(“New York”) chennai.show_me newyork.show_me -------------------------------------- Chennai New York Local Variable class Place def initialize(place) @current_place = place end def show_me puts @current_place end end
28. Constants class Place MYVAR = 100 def show_me puts “Value of constant is #{MYVAR}” end end Output: chennai =Place.new(“Chennai”) chennai.show_me -------------------------------------- Value of constant is 100
29. a version manager (RVM or rbenv or other) Install ruby using
30. Thank You!