From: Robert Klemme <shortcutter@...>
Date: 2006-12-31T23:00:08+09:00
Subject: Re: Newbie: It works, how can I make it better?

On 30.12.2006 21:02, Jay Bornhoft wrote:
> I wrote this little prog giving the user two choices.
> 
> I would really appreciate any advice on how I can improve anything about
> this program (structure, layout, etc)

Since you're doing a single conversion only, you could as well use 
command line arguments.  I have also added automatic detection of the 
conversion direction with Fahrenheit being the default input value using 
regular expressions.  You could use that technique in an interactive 
version as well thus improving usability (because you do have to enter 
one value only vs. two values).

Sample execution

$ ruby cf.rb 10c "10 f" 20

Temperature conversion

+10.0C is -12.2F
+10.0F is +50.0C
+20.0F is +68.0C

Kind regards

	robert


puts <<HEAD

Temperature conversion

HEAD

ARGV.each do |val|
   case val
     when /^(\d+)(?:\s*f)?$/i
       celsius = $1.to_f
       printf "%+3.1fF is %+3.1fC\n", celsius, (celsius * 1.8) + 32
     when /^(\d+)\s*c$/i
       fahrenheit = $1.to_f
       printf "%+3.1fC is %+3.1fF\n", fahrenheit, (fahrenheit - 32) / 1.8
     else
       $stderr.puts "ERROR: could not convert '#{val}'"
   end
end