class Integer

# File lib/motion-steward/app_store_research.rb, line 5
def commas
  self            #=> 12345678
    .to_s             #=> "12345678"
    .reverse          #=> "87654321"
    .scan(/\d{1,3}/)  #=> ["876","543","21"]
    .join(",")        #=> "876,543,21"
    .reverse          #=> "12,345,678"
end