random_code_generator.rb

# Generates a random string of letters and numbers

letters = ('A'..'Z').to_a

print 'Length of random string? '; length_of_string = gets.chomp.to_i
print 'How many to make? '; number_to_make = gets.chomp.to_i

numbers = []
while numbers.length < number_to_make do
  output = ''
  length_of_string.times { rand(2) == 1 ? output += letters[rand(26)].to_s : output += rand(10).to_s }
  numbers << output unless numbers.include? output
end

puts numbers.inspect

#
# Sample output
#
# Length of random string? 10
# How many to make? 5
# -> ["6E98YT8336", "D238RU98RO", "I6701D484D", "BWP8EBC2R6", "2634HDD15D"]
#