Ruby Variables and Constants

var-const.rb

#!/usr/bin/env ruby

# Ruby Variables and Constants

module M
  variable = 1
  CONSTANT = 2

  variable = 3
  # IMMUTABILITY is not guaranteed
  remove_const :CONSTANT
  CONSTANT = 4

  begin
    # UPPERCASE is needed
    const_set :constant, 5
  rescue => e
    puts e
  end
end

puts "M::variable: #{M::variable rescue 'oops'}"
# constants are PERSISTENT
puts "M::CONSTANT: #{M::CONSTANT}"