This document discusses JRuby and Ruby programming concepts like object orientation, data types, blocks, and Ruby on Rails. It is a presentation that introduces JRuby, which allows Ruby code to run on the Java Virtual Machine. It highlights features of Ruby like dynamically typed variables, multi-paradigm programming, metaprogramming, and object orientation. Data types in Ruby like arrays, hashes, and symbols are demonstrated. Blocks and yielding in Ruby are shown as an alternative to for loops. Rails is introduced at the end along with building a sample Rails application. The document serves to educate about Ruby and promote following the Twitter handle @vagmi for more information.

1. JRUBY
A Better Java and A Better Ruby - by Vagmi Mudumbai

2. Who am I
http://www.dharanasoft.com
RailsPundit
http://www.railspundit.com

3. I hack on
Follow me @vagmi

4. Dynamically Typed
MyCollection<IMyInteface> myCollection = new MyCollection<IMyInterface>()
my_collection = MyCollection.new
Follow me @vagmi

5. Multi Paradigm Language
Follow me @vagmi

6. Meta programming
You just have to realize
There is no spoon!
Follow me @vagmi

7. Talk is cheap.
Show me the code.
Follow me @vagmi

8. Object Orientation
5.class
=> Fixnum
class Sample
class Sample
def hello2
def hello
puts “hello2”
puts “hello”
end
end
end
end
obj.hello2
obj = Sample.new
obj.hello
Follow me @vagmi

9. Object Orientation
class << obj2
def hello3
obj2 = Sample.new
puts “hello3”
obj2.hello1
end
hello
end
=> nil
obj2.hello3
obj2.hello2
hello3
hello2
=> nil
=> nil
obj.hello3
# error occurs
Follow me @vagmi

10. Data Types
a = [1,2,3,”hello”,[‘a’,’b’,’c’]
a << “another object” hsh = {}
a[4] hsh = {“a”=>1, “b”=>2}
=> “hello” hsh = {“asdf”=>1,2=>”asdf”}
a[4] hsh[a] = “key can be anything”
=>[‘a’,’b’,’c’]
Follow me @vagmi

11. Data Types
“asdf”.object_id
=>id1
“asdf”.object_id
=>id2
to the rescue
Strings are mu table. Symbols
:”asdf”.object_id
=> id3
:”asdf”.object_id
=> id3
:asdf.object_id
=> id3
Follow me @vagmi

12. Blocks
Ruby has no for statement
Follow me @vagmi

13. Blocks
[1,2,3,4].each do |i|
puts (i*2).to_s def measure_it(&block)
end puts Time.now
2 yield
4 puts Time.now
6 end
8
Follow me @vagmi

14. But why JRuby
quartz-jruby
http://blog.dharanasoft.com/2010/12/03/scheduling-
jobs-with-jruby/
Follow me @vagmi

15. Introducing Rails
Follow me @vagmi

16. Lets build a Rails App
Follow me @vagmi

17. Questions
Follow me now
@vagmi