Format with to_s Methods ActiveSupport Provides
Today I learned/remembered that to format a number with a delimiter, we can use ActiveSupport::NumericWithFormat#to_s(:delimited).
require 'active_support' require 'active_support/core_ext' 123456789.to_s(:delimited) # => "123,456,789" Not only that, but this method also provides other formats and takes options to tweak its behavior.
123456789.to_s(:delimited, delimiter: '-') # => "123-456-789" 123456789.to_s(:currency, precision: 3) # => "$123,456,789.000" 123456789.to_s(:human_size) # => "118 MB" 123456789.to_s(:human) # => "123 Million" Originally, when I need to format a number to a delimited number, I would try to use number_to_delimited provided by ActiveSupport::NumberHelper. But to_s is handy when we have to do that where the helper is not reachable by default, such as in a serializer class for ActiveModel Serializer. Calling this method passing a format is the same as calling ActiveSupport::NumberHelper.number_to_#{format}.
