Methods
N
Constants
DEFAULTS = { # Used in number_to_delimited # These are also the defaults for 'currency', 'percentage', 'precision', and 'human' format: { # Sets the separator between the units, for more precision (e.g. 1.0 / 2.0 == 0.5) separator: ".", # Delimits thousands (e.g. 1,000,000 is a million) (always in groups of three) delimiter: ",", # Number of decimals, behind the separator (the number 1 with a precision of 2 gives: 1.00) precision: 3, # If set to true, precision will mean the number of significant digits instead # of the number of decimal digits (1234 with precision 2 becomes 1200, 1.23543 becomes 1.2) significant: false, # If set, the zeros after the decimal separator will always be stripped (eg.: 1.200 will be 1.2) strip_insignificant_zeros: false }, # Used in number_to_currency currency: { format: { format: "%u%n", negative_format: "-%u%n", unit: "$", # These five are to override number.format and are optional separator: ".", delimiter: ",", precision: 2, significant: false, strip_insignificant_zeros: false } }, # Used in number_to_percentage percentage: { format: { delimiter: "", format: "%n%" } }, # Used in number_to_rounded precision: { format: { delimiter: "" } }, # Used in number_to_human_size and number_to_human human: { format: { # These five are to override number.format and are optional delimiter: "", precision: 3, significant: true, strip_insignificant_zeros: true }, # Used in number_to_human_size storage_units: { # Storage units output formatting. # %u is the storage unit, %n is the number (default: 2 MB) format: "%n %u", units: { byte: "Bytes", kb: "KB", mb: "MB", gb: "GB", tb: "TB" } }, # Used in number_to_human decimal_units: { format: "%n %u", # Decimal units output formatting # By default we will only quantify some of the exponents # but the commented ones might be defined or overridden # by the user. units: { # femto: Quadrillionth # pico: Trillionth # nano: Billionth # micro: Millionth # mili: Thousandth # centi: Hundredth # deci: Tenth unit: "", # ten: # one: Ten # other: Tens # hundred: Hundred thousand: "Thousand", million: "Million", billion: "Billion", trillion: "Trillion", quadrillion: "Quadrillion" } } } }
 
DECIMAL_UNITS = { 0 => :unit, 1 => :ten, 2 => :hundred, 3 => :thousand, 6 => :million, 9 => :billion, 12 => :trillion, 15 => :quadrillion, -1 => :deci, -2 => :centi, -3 => :mili, -6 => :micro, -9 => :nano, -12 => :pico, -15 => :femto }
 
STORAGE_UNITS = [:byte, :kb, :mb, :gb, :tb]
 
Instance Public methods
number_to_currency(number, options = {})

Formats a number into a currency string (e.g., $13.65). You can customize the format in the options hash.

Options

  • :locale - Sets the locale to be used for formatting (defaults to current locale).

  • :precision - Sets the level of precision (defaults to 2).

  • :unit - Sets the denomination of the currency (defaults to “$”).

  • :separator - Sets the separator between the units (defaults to “.”).

  • :delimiter - Sets the thousands delimiter (defaults to “,”).

  • :format - Sets the format for non-negative numbers (defaults to “%u%n”). Fields are %u for the currency, and %n for the number.

  • :negative_format - Sets the format for negative numbers (defaults to prepending an hyphen to the formatted number given by :format). Accepts the same fields than :format, except %n is here the absolute value of the number.

Examples

number_to_currency(1234567890.50)                # => $1,234,567,890.50
number_to_currency(1234567890.506)               # => $1,234,567,890.51
number_to_currency(1234567890.506, precision: 3) # => $1,234,567,890.506
number_to_currency(1234567890.506, locale: :fr)  # => 1 234 567 890,51 €
number_to_currency('123a456')                    # => $123a456

number_to_currency(-1234567890.50, negative_format: '(%u%n)')
# => ($1,234,567,890.50)
number_to_currency(1234567890.50, unit: '£', separator: ',', delimiter: '')
# => £1234567890,50
number_to_currency(1234567890.50, unit: '£', separator: ',', delimiter: '', format: '%n %u')
# => 1234567890,50 £
# File activesupport/lib/active_support/number_helper.rb, line 201
def number_to_currency(number, options = {})
  return unless number
  options = options.symbolize_keys

  currency = i18n_format_options(options[:locale], :currency)
  currency[:negative_format] ||= "-" + currency[:format] if currency[:format]

  defaults  = default_format_options(:currency).merge!(currency)
  defaults[:negative_format] = "-" + options[:format] if options[:format]
  options   = defaults.merge!(options)

  unit      = options.delete(:unit)
  format    = options.delete(:format)

  if number.to_f.phase != 0
    format = options.delete(:negative_format)
    number = number.respond_to?("abs") ? number.abs : number.sub(/^-/, '')
  end

  format.gsub('%n', self.number_to_rounded(number, options)).gsub('%u', unit)
end
number_to_delimited(number, options = {})

Formats a number with grouped thousands using delimiter (e.g., 12,324). You can customize the format in the options hash.

Options

  • :locale - Sets the locale to be used for formatting (defaults to current locale).

  • :delimiter - Sets the thousands delimiter (defaults to “,”).

  • :separator - Sets the separator between the fractional and integer digits (defaults to “.”).

Examples

number_to_delimited(12345678)                    # => 12,345,678
number_to_delimited('123456')                    # => 123,456
number_to_delimited(12345678.05)                 # => 12,345,678.05
number_to_delimited(12345678, delimiter: '.')    # => 12.345.678
number_to_delimited(12345678, delimiter: ',')    # => 12,345,678
number_to_delimited(12345678.05, separator: ' ') # => 12,345,678 05
number_to_delimited(12345678.05, locale: :fr)    # => 12 345 678,05
number_to_delimited('112a')                      # => 112a
number_to_delimited(98765432.98, delimiter: ' ', separator: ',')
# => 98 765 432,98
# File activesupport/lib/active_support/number_helper.rb, line 291
def number_to_delimited(number, options = {})
  options = options.symbolize_keys

  return number unless valid_float?(number)

  options = format_options(options[:locale]).merge!(options)

  parts = number.to_s.split('.')
  parts[0].gsub!(/(\d)(?=(\d\d\d)+(?!\d))/, "\\1#{options[:delimiter]}")
  parts.join(options[:separator])
end
number_to_human(number, options = {})

Pretty prints (formats and approximates) a number in a way it is more readable by humans (eg.: 1200000000 becomes “1.2 Billion”). This is useful for numbers that can get very large (and too hard to read).

See number_to_human_size if you want to print a file size.

You can also define your own unit-quantifier names if you want to use other decimal units (eg.: 1500 becomes “1.5 kilometers”, 0.150 becomes “150 milliliters”, etc). You may define a wide range of unit quantifiers, even fractional ones (centi, deci, mili, etc).

Options

  • :locale - Sets the locale to be used for formatting (defaults to current locale).

  • :precision - Sets the precision of the number (defaults to 3).

  • :significant - If true, precision will be the # of significant_digits. If false, the # of fractional digits (defaults to true)

  • :separator - Sets the separator between the fractional and integer digits (defaults to “.”).

  • :delimiter - Sets the thousands delimiter (defaults to “”).

  • :strip_insignificant_zeros - If true removes insignificant zeros after the decimal separator (defaults to true)

  • :units - A Hash of unit quantifier names. Or a string containing an i18n scope where to find this hash. It might have the following keys:

    • integers: :unit, :ten, *:hundred, :thousand, :million, *:billion, :trillion, *:quadrillion

    • fractionals: :deci, :centi, *:mili, :micro, :nano, *:pico, :femto

  • :format - Sets the format of the output string (defaults to “%n %u”). The field types are:

    • %u - The quantifier (ex.: 'thousand')

    • %n - The number

Examples

number_to_human(123)                         # => "123"
number_to_human(1234)                        # => "1.23 Thousand"
number_to_human(12345)                       # => "12.3 Thousand"
number_to_human(1234567)                     # => "1.23 Million"
number_to_human(1234567890)                  # => "1.23 Billion"
number_to_human(1234567890123)               # => "1.23 Trillion"
number_to_human(1234567890123456)            # => "1.23 Quadrillion"
number_to_human(1234567890123456789)         # => "1230 Quadrillion"
number_to_human(489939, precision: 2)        # => "490 Thousand"
number_to_human(489939, precision: 4)        # => "489.9 Thousand"
number_to_human(1234567, precision: 4,
                         significant: false) # => "1.2346 Million"
number_to_human(1234567, precision: 1,
                         separator: ',',
                         significant: false) # => "1,2 Million"

Non-significant zeros after the decimal separator are stripped out by default (set :strip_insignificant_zeros to false to change that):

number_to_human(12345012345, significant_digits: 6) # => "12.345 Billion"
number_to_human(500000000, precision: 5)            # => "500 Million"

Custom Unit Quantifiers

You can also use your own custom unit quantifiers:

number_to_human(500000, units: { unit: 'ml', thousand: 'lt' })  # => "500 lt"

If in your I18n locale you have:

distance:
  centi:
    one: "centimeter"
    other: "centimeters"
  unit:
    one: "meter"
    other: "meters"
  thousand:
    one: "kilometer"
    other: "kilometers"
  billion: "gazillion-distance"

Then you could do:

number_to_human(543934, units: :distance)            # => "544 kilometers"
number_to_human(54393498, units: :distance)          # => "54400 kilometers"
number_to_human(54393498000, units: :distance)       # => "54.4 gazillion-distance"
number_to_human(343, units: :distance, precision: 1) # => "300 meters"
number_to_human(1, units: :distance)                 # => "1 meter"
number_to_human(0.34, units: :distance)              # => "34 centimeters"
# File activesupport/lib/active_support/number_helper.rb, line 552
def number_to_human(number, options = {})
  options = options.symbolize_keys

  return number unless valid_float?(number)
  number = Float(number)

  defaults = format_options(options[:locale], :human)
  options  = defaults.merge!(options)

  #for backwards compatibility with those that didn't add strip_insignificant_zeros to their locale files
  options[:strip_insignificant_zeros] = true if not options.key?(:strip_insignificant_zeros)

  inverted_du = DECIMAL_UNITS.invert

  units = options.delete :units
  unit_exponents = case units
  when Hash
    units
  when String, Symbol
    I18n.translate(:"#{units}", :locale => options[:locale], :raise => true)
  when nil
    translate_number_value_with_default("human.decimal_units.units", :locale => options[:locale], :raise => true)
  else
    raise ArgumentError, ":units must be a Hash or String translation scope."
  end.keys.map{|e_name| inverted_du[e_name] }.sort_by{|e| -e}

  number_exponent = number != 0 ? Math.log10(number.abs).floor : 0
  display_exponent = unit_exponents.find{ |e| number_exponent >= e } || 0
  number  /= 10 ** display_exponent

  unit = case units
  when Hash
    units[DECIMAL_UNITS[display_exponent]] || ''
  when String, Symbol
    I18n.translate(:"#{units}.#{DECIMAL_UNITS[display_exponent]}", :locale => options[:locale], :count => number.to_i)
  else
    translate_number_value_with_default("human.decimal_units.units.#{DECIMAL_UNITS[display_exponent]}", :locale => options[:locale], :count => number.to_i)
  end

  decimal_format = options[:format] || translate_number_value_with_default('human.decimal_units.format', :locale => options[:locale])
  formatted_number = self.number_to_rounded(number, options)
  decimal_format.gsub(/%n/, formatted_number).gsub(/%u/, unit).strip
end
number_to_human_size(number, options = {})

Formats the bytes in number into a more understandable representation (e.g., giving it 1500 yields 1.5 KB). This method is useful for reporting file sizes to users. You can customize the format in the options hash.

See number_to_human if you want to pretty-print a generic number.

Options

  • :locale - Sets the locale to be used for formatting (defaults to current locale).

  • :precision - Sets the precision of the number (defaults to 3).

  • :significant - If true, precision will be the # of significant_digits. If false, the # of fractional digits (defaults to true)

  • :separator - Sets the separator between the fractional and integer digits (defaults to “.”).

  • :delimiter - Sets the thousands delimiter (defaults to “”).

  • :strip_insignificant_zeros - If true removes insignificant zeros after the decimal separator (defaults to true)

  • :prefix - If :si formats the number using the SI prefix (defaults to :binary)

Examples

number_to_human_size(123)                                    # => 123 Bytes
number_to_human_size(1234)                                   # => 1.21 KB
number_to_human_size(12345)                                  # => 12.1 KB
number_to_human_size(1234567)                                # => 1.18 MB
number_to_human_size(1234567890)                             # => 1.15 GB
number_to_human_size(1234567890123)                          # => 1.12 TB
number_to_human_size(1234567, precision: 2)                  # => 1.2 MB
number_to_human_size(483989, precision: 2)                   # => 470 KB
number_to_human_size(1234567, precision: 2, separator: ',')  # => 1,2 MB

Non-significant zeros after the fractional separator are stripped out by default (set :strip_insignificant_zeros to false to change that):

number_to_human_size(1234567890123, precision: 5) # => "1.1229 TB"
number_to_human_size(524288000, precision: 5)     # => "500 MB"
# File activesupport/lib/active_support/number_helper.rb, line 422
def number_to_human_size(number, options = {})
  options = options.symbolize_keys

  return number unless valid_float?(number)
  number = Float(number)

  defaults = format_options(options[:locale], :human)
  options  = defaults.merge!(options)

  #for backwards compatibility with those that didn't add strip_insignificant_zeros to their locale files
  options[:strip_insignificant_zeros] = true if not options.key?(:strip_insignificant_zeros)

  storage_units_format = translate_number_value_with_default('human.storage_units.format', :locale => options[:locale], :raise => true)

  base = options[:prefix] == :si ? 1000 : 1024

  if number.to_i < base
    unit = translate_number_value_with_default('human.storage_units.units.byte', :locale => options[:locale], :count => number.to_i, :raise => true)
    storage_units_format.gsub(/%n/, number.to_i.to_s).gsub(/%u/, unit)
  else
    max_exp  = STORAGE_UNITS.size - 1
    exponent = (Math.log(number) / Math.log(base)).to_i # Convert to base
    exponent = max_exp if exponent > max_exp # we need this to avoid overflow for the highest unit
    number  /= base ** exponent

    unit_key = STORAGE_UNITS[exponent]
    unit = translate_number_value_with_default("human.storage_units.units.#{unit_key}", :locale => options[:locale], :count => number, :raise => true)

    formatted_number = self.number_to_rounded(number, options)
    storage_units_format.gsub(/%n/, formatted_number).gsub(/%u/, unit)
  end
end
number_to_percentage(number, options = {})

Formats a number as a percentage string (e.g., 65%). You can customize the format in the options hash.

Options

  • :locale - Sets the locale to be used for formatting (defaults to current locale).

  • :precision - Sets the precision of the number (defaults to 3).

  • :significant - If true, precision will be the # of significant_digits. If false, the # of fractional digits (defaults to false).

  • :separator - Sets the separator between the fractional and integer digits (defaults to “.”).

  • :delimiter - Sets the thousands delimiter (defaults to “”).

  • :strip_insignificant_zeros - If true removes insignificant zeros after the decimal separator (defaults to false).

  • :format - Specifies the format of the percentage string The number field is %n (defaults to “%n%”).

Examples

number_to_percentage(100)                                  # => 100.000%
number_to_percentage('98')                                 # => 98.000%
number_to_percentage(100, precision: 0)                    # => 100%
number_to_percentage(1000, delimiter: '.', separator: ',') # => 1.000,000%
number_to_percentage(302.24398923423, precision: 5)        # => 302.24399%
number_to_percentage(1000, locale: :fr)                    # => 1 000,000%
number_to_percentage('98a')                                # => 98a%
number_to_percentage(100, format: '%n  %')                 # => 100  %
# File activesupport/lib/active_support/number_helper.rb, line 255
def number_to_percentage(number, options = {})
  return unless number
  options = options.symbolize_keys

  defaults = format_options(options[:locale], :percentage)
  options  = defaults.merge!(options)

  format = options[:format] || "%n%"
  format.gsub('%n', self.number_to_rounded(number, options))
end
number_to_phone(number, options = {})

Formats a number into a US phone number (e.g., (555) 123-9876). You can customize the format in the options hash.

Options

  • :area_code - Adds parentheses around the area code.

  • :delimiter - Specifies the delimiter to use (defaults to “-”).

  • :extension - Specifies an extension to add to the end of the generated number.

  • :country_code - Sets the country code for the phone number.

Examples

number_to_phone(5551234)                                     # => 555-1234
number_to_phone('5551234')                                   # => 555-1234
number_to_phone(1235551234)                                  # => 123-555-1234
number_to_phone(1235551234, area_code: true)                 # => (123) 555-1234
number_to_phone(1235551234, delimiter: ' ')                  # => 123 555 1234
number_to_phone(1235551234, area_code: true, extension: 555) # => (123) 555-1234 x 555
number_to_phone(1235551234, country_code: 1)                 # => +1-123-555-1234
number_to_phone('123a456')                                   # => 123a456

number_to_phone(1235551234, country_code: 1, extension: 1343, delimiter: '.')
# => +1.123.555.1234 x 1343
# File activesupport/lib/active_support/number_helper.rb, line 139
def number_to_phone(number, options = {})
  return unless number
  options = options.symbolize_keys

  number       = number.to_s.strip
  area_code    = options[:area_code]
  delimiter    = options[:delimiter] || "-"
  extension    = options[:extension]
  country_code = options[:country_code]

  if area_code
    number.gsub!(/(\d{1,3})(\d{3})(\d{4}$)/,"(\\1) \\2#{delimiter}\\3")
  else
    number.gsub!(/(\d{0,3})(\d{3})(\d{4})$/,"\\1#{delimiter}\\2#{delimiter}\\3")
    number.slice!(0, 1) if number.start_with?(delimiter) && !delimiter.blank?
  end

  str = ''
  str << "+#{country_code}#{delimiter}" unless country_code.blank?
  str << number
  str << " x #{extension}" unless extension.blank?
  str
end
number_to_rounded(number, options = {})

Formats a number with the specified level of :precision (e.g., 112.32 has a precision of 2 if :significant is false, and 5 if :significant is true). You can customize the format in the options hash.

Options

  • :locale - Sets the locale to be used for formatting (defaults to current locale).

  • :precision - Sets the precision of the number (defaults to 3).

  • :significant - If true, precision will be the # of significant_digits. If false, the # of fractional digits (defaults to false).

  • :separator - Sets the separator between the fractional and integer digits (defaults to “.”).

  • :delimiter - Sets the thousands delimiter (defaults to “”).

  • :strip_insignificant_zeros - If true removes insignificant zeros after the decimal separator (defaults to false).

Examples

number_to_rounded(111.2345)                                  # => 111.235
number_to_rounded(111.2345, precision: 2)                    # => 111.23
number_to_rounded(13, precision: 5)                          # => 13.00000
number_to_rounded(389.32314, precision: 0)                   # => 389
number_to_rounded(111.2345, significant: true)               # => 111
number_to_rounded(111.2345, precision: 1, significant: true) # => 100
number_to_rounded(13, precision: 5, significant: true)       # => 13.000
number_to_rounded(111.234, locale: :fr)                      # => 111,234

number_to_rounded(13, precision: 5, significant: true, strip_insignificant_zeros: true)
# => 13

number_to_rounded(389.32314, precision: 4, significant: true) # => 389.3
number_to_rounded(1111.2345, precision: 2, separator: ',', delimiter: '.')
# => 1.111,23
# File activesupport/lib/active_support/number_helper.rb, line 342
def number_to_rounded(number, options = {})
  return number unless valid_float?(number)
  number  = Float(number)
  options = options.symbolize_keys

  defaults = format_options(options[:locale], :precision)
  options  = defaults.merge!(options)

  precision = options.delete :precision
  significant = options.delete :significant
  strip_insignificant_zeros = options.delete :strip_insignificant_zeros

  if significant && precision > 0
    if number == 0
      digits, rounded_number = 1, 0
    else
      digits = (Math.log10(number.abs) + 1).floor
      multiplier = 10 ** (digits - precision)
      rounded_number = (BigDecimal.new(number.to_s) / BigDecimal.new(multiplier.to_f.to_s)).round.to_f * multiplier
      digits = (Math.log10(rounded_number.abs) + 1).floor # After rounding, the number of digits may have changed
    end
    precision -= digits
    precision = 0 if precision < 0 # don't let it be negative
  else
    rounded_number = BigDecimal.new(number.to_s).round(precision).to_f
    rounded_number = rounded_number.abs if rounded_number.zero? # prevent showing negative zeros
  end
  formatted_number = self.number_to_delimited("%01.#{precision}f" % rounded_number, options)
  if strip_insignificant_zeros
    escaped_separator = Regexp.escape(options[:separator])
    formatted_number.sub(/(#{escaped_separator})(\d*[1-9])?0+\z/, '\1\2').sub(/#{escaped_separator}\z/, '')
  else
    formatted_number
  end
end