From: John Kaurin <jkaurin@...>
Date: 2001-11-03T13:09:00+09:00
Subject: [ruby-talk:24247] Re: Thousand Separator

"Wai-Sun Chia" <waisun.chia@msa.dec.com> wrote in message news:3BE0D1C6.7090703@msa.dec.com...
| Hello,
| I'm in the need of a thousand separator method which takes in a number
| and spits it back out nicely separated with the current locale's
| thousand separator (',' in my case).
|
| This is something like PHP's number_format() or printf()'s '%'f'...
| Anybody did something like this?
|
|
|
|
| --
| Wai-Sun "Squidster" Chia
| RHCE/Professional Services
| Linux/Unix/Web Developer
|
|

Here is a thought starter, not very robust.

  def commafy(number)

  # Reverse the digits that make up the number to ease processing.

    number = number.to_s.reverse

  # Add commas in the appropriate places.

    number.gsub!(/(\d\d\d)(?=\d)(?!\d*\.)/) do |match|
      $1 + ','
    end

  # Reverse the result back to the proper form.

    number = number.to_s.reverse

  end

  puts commafy(100000000) # => 100,000,000
  puts commafy(100000.01) # => 100,000.01
  puts commafy(-10000000) # => -10,000,000
  puts commafy(-10000.00) # => -10,000.0
  puts commafy(123456.70) # => 123,456.7
  puts commafy(123.45600) # => 123.456
  puts commafy(123.45e10) # => 1.2345e+12
  puts commafy(1234.5e10) # => 1.2345e+13
  puts commafy(1234.5067) # => 1,234.5067
  puts commafy(1.2345678) # => 1.2345678
  puts 123.4560.to_s      # => 123.456
  puts 123.4560.to_a      # => 123.456