fizzbuzz_01.rb

count = 1
while count <= 100
  if count % 3 == 0 && count % 5 == 0
    puts 'FizzBuzz'
  elsif count % 3 == 0
    puts 'Fizz'
  elsif count % 5 == 0
    puts 'Buzz'
  else
    puts count
  end
  count += 1
end

fizzbuzz_02.rb

(1..100).each do |i|
  puts case
       when i % 15 == 0 then 'FizzBuzz'
       when i % 3 == 0 then 'Fizz'
       when i % 5 == 0 then 'Buzz'
       else i
       end
end

fizzbuzz_03.rb

(1..100).each { |i| puts i % 15 == 0 ? :FizzBuzz : i % 3 == 0 ? :Fizz : i % 5 == 0 ? :Buzz : i }

fizzbuzz_04.rb

puts (1..100).map { |i| i % 15 == 0 ? :FizzBuzz : i % 3 == 0 ? :Fizz : i % 5 == 0 ? :Buzz : i }.join("\n")