address_regex.rb

regex = Regexp.new(/^[0-9]* (.*), (.*) [a-zA-Z]{2} [0-9]{5}(-[0-9]{4})?$/)
addresses = ["420 Fanboy Lane, Cupertino CA 12345"]
addresses << "1829 William Tell Oveture, by Gioachino Rossini 88421"
addresses << "114801 Western East Avenue Apt. B32, Funky Township CA 12345"
addresses << "1 Infinite Loop, Cupertino CA 12345-1234"
addresses << "420 time!"

addresses.each do |address|
  print address
  if address.match(regex)
    puts " is an address"
  else
    puts " is not an address"
  end
end

# Outputs:
> 420 Fanboy Lane, Cupertino CA 12345 is an address  
> 1829 William Tell Oveture, by Gioachino Rossini 88421 is not an address  
> 114801 Western East Avenue Apt. B32, Funky Township CA 12345 is an address  
> 1 Infinite Loop, Cupertino CA 12345-1234 is an address  
> 420 time! is not an address