Basics

Hello World

hello_world.rb

puts "Hello World !"

# this is a comment

Execute

ruby hello_world.ruby

Interactive Ruby Shell (IRB)

irb

quit

Documentation

Ruby Programming Languageruby-lang.org

Ruby-Doc.org: Documenting the Ruby Languageruby-doc.org

Documentation using Command Line

ri String

ri String#upcase

ri String.new