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Provides methods for converting numbers into formatted strings. Methods are provided for phone numbers, currency, percentage, precision, positional notation, file size and pretty printing.

Most methods expect a number argument, and will return it unchanged if can't be converted into a valid number.

Namespace
Methods
N
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.

  • :raise - If true, raises InvalidNumberError when the argument is invalid.

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("123a456", raise: true)           # => InvalidNumberError

number_to_currency(-1234567890.50, negative_format: "(%u%n)")
# => ($1,234,567,890.50)
number_to_currency(1234567890.50, unit: "R$", separator: ",", delimiter: "")
# => R$1234567890,50
number_to_currency(1234567890.50, unit: "R$", separator: ",", delimiter: "", format: "%n %u")
# => 1234567890,50 R$
# File actionview/lib/action_view/helpers/number_helper.rb, line 106
def number_to_currency(number, options = {})
  delegate_number_helper_method(:number_to_currency, number, options)
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 you 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

  • :raise - If true, raises InvalidNumberError when the argument is invalid.

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"

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

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

#number_to_human(12.00001) # => “12” #number_to_human(12.00001, strip_insignificant_zeros: false) # => “12.0”

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 actionview/lib/action_view/helpers/number_helper.rb, line 376
def number_to_human(number, options = {})
  delegate_number_helper_method(:number_to_human, number, options)
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)

  • :raise - If true, raises InvalidNumberError when the argument is invalid.

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
number_to_human_size(1234567890123, precision: 5)                  # => "1.1228 TB"
number_to_human_size(524288000, precision: 5)                      # => "500 MB"
# File actionview/lib/action_view/helpers/number_helper.rb, line 270
def number_to_human_size(number, options = {})
  delegate_number_helper_method(:number_to_human_size, number, options)
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%”).

  • :raise - If true, raises InvalidNumberError when the argument is invalid.

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  %

number_to_percentage("98a", raise: true)                         # => InvalidNumberError
# File actionview/lib/action_view/helpers/number_helper.rb, line 146
def number_to_percentage(number, options = {})
  delegate_number_helper_method(:number_to_percentage, 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.

  • :raise - If true, raises InvalidNumberError when the argument is invalid.

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("1234a567", raise: true)                           # => InvalidNumberError

number_to_phone(1235551234, country_code: 1, extension: 1343, delimiter: ".")
# => +1.123.555.1234 x 1343
# File actionview/lib/action_view/helpers/number_helper.rb, line 56
def number_to_phone(number, options = {})
  return unless number
  options = options.symbolize_keys

  parse_float(number, true) if options.delete(:raise)
  ERB::Util.html_escape(ActiveSupport::NumberHelper.number_to_phone(number, options))
end
number_with_delimiter(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 “.”).

  • :raise - If true, raises InvalidNumberError when the argument is invalid.

Examples

 number_with_delimiter(12345678)                        # => 12,345,678
 number_with_delimiter("123456")                        # => 123,456
 number_with_delimiter(12345678.05)                     # => 12,345,678.05
 number_with_delimiter(12345678, delimiter: ".")        # => 12.345.678
 number_with_delimiter(12345678, delimiter: ",")        # => 12,345,678
 number_with_delimiter(12345678.05, separator: " ")     # => 12,345,678 05
 number_with_delimiter(12345678.05, locale: :fr)        # => 12 345 678,05
 number_with_delimiter("112a")                          # => 112a
 number_with_delimiter(98765432.98, delimiter: " ", separator: ",")
 # => 98 765 432,98

number_with_delimiter("112a", raise: true)              # => raise InvalidNumberError
# File actionview/lib/action_view/helpers/number_helper.rb, line 179
def number_with_delimiter(number, options = {})
  delegate_number_helper_method(:number_to_delimited, number, options)
end
number_with_precision(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).

  • :raise - If true, raises InvalidNumberError when the argument is invalid.

Examples

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

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

number_with_precision(389.32314, precision: 4, significant: true)       # => 389.3
number_with_precision(1111.2345, precision: 2, separator: ',', delimiter: '.')
# => 1.111,23
# File actionview/lib/action_view/helpers/number_helper.rb, line 224
def number_with_precision(number, options = {})
  delegate_number_helper_method(:number_to_rounded, number, options)
end