How can I generate random mixed letters and numbers in Ruby

Question

I have the following code so far, this generates letters only. I am looking to get both letters and numbers

#Generate random 8 digit number and output to file
    output = File.new("C:/Users/%user%/Desktop/Strings.txt", "w")

    i = 0
     while i < 500
        randomer = (0...8).map{65.+(rand(26)).chr}.join
        output << randomer
        output << "\n"
        i = i+1
     end

    output.close

Answer 1

How about this:

def random_tuple(length)
    letters_and_numbers = "abcdefghijklmnopqrstuvwxyz0123456789"
    answer = ""
    length.times { |i| answer << letters_and_numbers[rand(36)] }
    answer
end

output = ""
500.times { |i| output << random_tuple(8) + "\n" }

You could also have the function append the newline, but I think this way is more general.