Introduction to Ruby Andrew Liu 

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! 

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. 

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

Everything is an object! 

Strings 

String Methods 

Array 

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

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Range 

Hash 

Block 

How does it work? 

More About Class 

More About Class 

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 

Creating Instance 

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Flow Control 

Cases 

While 

For 

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