Numer drukowania szyn z przestrzenią
number.to_s.reverse.scan(/\d{1,3}/).join(",").reverse
number #=> 12345678
.to_s #=> "12345678"
.reverse #=> "87654321"
.scan(/\d{1,3}/) #=> ["876","543","21"]
.join(",") #=> "876,543,21"
.reverse #=> "12,345,678"
Lioruby