Learn to Program, 2nd Edition

Ranges

Range is another great class. Ranges represent intervals of numbers. On the next page is just a quick glance at some of the methods ranges have.

#  This is your range literal.
letters = 'a'..'c'
#  Convert range to array.
puts(['a','b','c'] == letters.to_a)
#  Iterate over a range:
('A'..'Z').each do |letter|
  print letter
end
puts
god_bless_the_70s = 1970..1979
puts god_bless_the_70s.min
puts god_bless_the_70s.max
puts(god_bless_the_70s.include?(1979  ))
puts(god_bless_the_70s.include?(1980  ))
puts(god_bless_the_70s.include?(1974.5))

true
ABCDEFGHIJKLMNOPQRSTUVWXYZ
1970
1979
true
false
true

Do you really need ranges? No, not really. It’s the same with hashes and times, I suppose. You can program fairly well without them (and most languages ...