How to format a number 1000 as "1 000"
see: http://www.justskins.com/forums/format-number-with-comma-37369.html
there is no built in way to it ( unless you using Rails, ActiveSupport Does have methods to do this) but you can use a Regex like
formatted_n = n.to_s.reverse.gsub(/...(?=.)/,'\&,').reverse
Activesupport uses this regexp (and no reverse reverse).
10000000.to_s.gsub(/(\d)(?=(\d\d\d)+(?!\d))/, "\\1 ") #=> "10 000 000"
Here's another method that is fairly clean and straightforward if you are dealing with integers:
number.to_s.reverse.scan(/\d{1,3}/).join(",").reversenumber #=> 12345678.to_s #=> "12345678".reverse #=> "87654321".scan(/\d{1,3}/) #=> ["876","543","21"].join(",") #=> "876,543,21".reverse #=> "12,345,678"Works great for integers. Of course, this particular example will separate the number by commas, but switching to spaces or any other separator is as simple as replacing the parameter in the join method.