Stupid and un-optimized converter to other numerical bases(NUMBER.to_s(base))

convert_number_to_base.rb

def convert(number, base=10)
  raise "base must be between 2 and 36" if base < 2 || base > 36
  negative = number < 0
  number = number.abs
  number_array = []
  loop do
    number_array.unshift("0123456789abcdefghijklmnopqrstuvwxyz"[number % base])
    number /= base
    break if number == 0
  end

  number_array.unshift("-") if negative

  number_array.join
end