I’m sure you’ve probably seen this question in your programming classes.. I decided I wanted to play with Ruby again and was remind of this problem, so thought it might be fun as a simple exercise to do this in Ruby.

The problem is to take a long integer and convert it to hours, minutes and seconds. This is a common issue in games, for example, where a countdown timer is represent internally in seconds. But players don’t want to see some huge number like 43678 seconds. They’d rather see 12:07:58 for hours, minutes and seconds. A couple of uses of the mod operator, and a couple of uses of the built-in formatter and you’re good to go.

Update: I wanted to clean up the code a bit more and put the ruby equivalent of a “main” via the __FILE__ check. This way you can just reuse the code via require if you so desire.

#!/usr/bin/env ruby

class TimeFormatter

  def format_time (timeElapsed)

    @timeElapsed = timeElapsed

    #find the seconds
    seconds = @timeElapsed % 60

    #find the minutes
    minutes = (@timeElapsed / 60) % 60

    #find the hours
    hours = (@timeElapsed/3600)

    #format the time

    return hours.to_s + ":" + format("%02d",minutes.to_s) + ":" + format("%02d",seconds.to_s)
  end
end

if __FILE__ == $0
  formatter = TimeFormatter.new

  puts formatter.format_time(43678)
end