block_sample.rb

#!/usr/bin/env ruby

def block_sample
  puts 'stand up'
  yield if block_given?
  puts 'sit down'
end

block_sample do
  puts 'walk'
end

block_sample()

catch_throw.rb

#!/usr/bin/env ruby

catch :triple_loop do
  loop do
    puts 'one'

    loop do
      puts 'two'

      loop do
        puts 'three'

        throw :triple_loop
      end
    end
  end
end

catch_throw2.rb

#!/usr/bin/env ruby

catch :entire do
  catch :process do
    throw :entire
  end
end