1. Introduction to Ruby
Andrew Liu

2. Ruby is…
• Designed by Yukihiro Matsumoto (松本行弘)
– "I wanted a scripting language that was more
powerful than Perl, and more object-
oriented than Python. That's why I decided to
design my own language“
• An object-oriented scripting language
• Easy to learn!

3. Philosophy
• Often people, especially computer engineers, focus
on the machines. They think, "By doing this, the
machine will run faster. By doing this, the machine
will run more effectively. By doing this, the machine
will something something something."
• They are focusing on machines. But in fact we need
to focus on humans, on how humans care about
doing programming or operating the application of
the machines. We are the masters. They are the
slaves.

5. Naming Convention
• CamelCase
– Class names, module names
• ALLCAPITAL
– Constants
• words_with_underscore
– Method names, variable names
• $ prefix
– Global variables

6. Everything is an object!

7. Strings

8. String Methods

9. Array

10. What if I want to reverse the array?
http://ruby-doc.org/core/

12. Range

13. Hash

14. Block

15. How does it work?

16. More About Class

17. More About Class

18. Class
• Variable
– @@ prefix: Shared by all class instances
– @ prefix: Contains instances information
– No prefix: normal variables
• Methods
– self. Prefix: Class methods, as known as static
method
– No prefix: Instance methods, must be called with
a instance

19. Creating Instance

21. Flow Control

22. Cases

23. While

24. For

25. Resources
• Programming Ruby (Bible)
– http://www.ruby-
doc.org/docs/ProgrammingRuby/
• Ruby API Document
– http://ruby-doc.org/core/
• TryRuby
– http://tryruby.org/
• Ruby Warrior
– https://github.com/ryanb/ruby-warrior