Difference between ranges and array

gistfile1.rb

require "benchmark"

char_collection = Hash.new (0)
TIMES = 10000
input_string = "123ABc ifuy fdtgbj\h vhkkkktvcv_*^%$# yku13234"

lowercase = ('a'..'z').to_a
uppercase = ('A'..'Z').to_a
digits = ('0'..'9').to_a
lcase = ('a'..'z')
ucase = ('A'..'Z')
dig = ('0'..'9')

Benchmark.bmbm do |test|
  test.report ("array include") do
    TIMES.times do |x|
      input_string.each_char do |char|
        case
        when lowercase.include?(char)
          char_collection['lowercase'] += 1
        when uppercase.include?(char)
          char_collection['uppercase'] += 1
        when digits.include?(char)
          char_collection['digits'] += 1
        else
          char_collection['special_characters'] += 1
        end
      end
      char_collection
    end
  end

  test.report ("array case") do
    TIMES.times do |x|
      input_string.each_char do |char|
        case char
        when lowercase
          char_collection['lowercase'] += 1
        when uppercase
          char_collection['uppercase'] += 1
        when digits
          char_collection['digits'] += 1
        else
          char_collection['special_characters'] += 1
        end
      end
      char_collection
    end
  end

  test.report("inline ranges") do
    TIMES.times do |x|
      input_string.each_char do |char|
        case char
        when 'a'..'z'
          char_collection['lowercase'] += 1
        when 'A'..'Z'
          char_collection['uppercase'] += 1
        when '0'..'9'
          char_collection['digit'] += 1
        else
          char_collection['special_characters'] += 1
        end
      end
      char_collection
    end
  end
  test.report ("preinitialized ranges") do
    TIMES.times do |x|
      input_string.each_char do |char|
        case char
        when lcase
          char_collection['lowercase'] += 1
        when ucase
          char_collection['uppercase'] += 1
        when dig
          char_collection['digits'] += 1
        else
          char_collection['special_characters'] += 1
        end
      end
      char_collection
    end
  end
end

Rehearsal ---------------------------------------------------------
array include           0.900000   0.000000   0.900000 (  0.902879)
array case              0.390000   0.000000   0.390000 (  0.383773)
inline ranges           0.660000   0.000000   0.660000 (  0.665557)
preinitialized ranges   0.350000   0.000000   0.350000 (  0.345596)
------------------------------------------------ total: 2.300000sec

                            user     system      total        real
array include           0.910000   0.000000   0.910000 (  0.917236)
array case              0.390000   0.010000   0.400000 (  0.384864)
inline ranges           0.660000   0.000000   0.660000 (  0.662120)
preinitialized ranges   0.340000   0.000000   0.340000 (  0.342905)