Cldr.Number.to_string
to_string
, go back to Cldr.Number module for more information.
Specs
to_string( number() | Decimal.t(), Cldr.backend() | Keyword.t() | map(), Keyword.t() | map() ) :: {:ok, String.t()} | {:error, {atom(), String.t()}}
Returns a number formatted into a string according to a format pattern and options.
Arguments
number
is an integer, float or Decimal to be formattedbackend
is anyCldr
backend. That is, any module that containsuse Cldr
options
is a keyword list defining how the number is to be formatted. The valid options are:
Options
format
: the format style or a format string defining how the number is formatted. SeeCldr.Number.Format
for how format strings can be constructed. SeeCldr.Number.Format.format_styles_for/3
to return available format styles for a locale. The defaultformat
is:standard
.If
:format
is set to:long
or:short
then the formatting depends on whether:currency
is specified. If not specified then the number is formatted as:decimal_long
or:decimal_short
. If:currency
is specified the number is formatted as:currency_long
or:currency_short
and:fractional_digits
is set to 0 as a default.:format
may also be a format defined by CLDR's Rules Based Number Formats (RBNF). Further information is found in the moduleCldr.Rbnf
. The most commonly used formats in this category are to spell out the number in a the locales language. The applicable formats are:spellout
,:spellout_year
,:ordinal
. A number can also be formatted as roman numbers by using the format:roman
or:roman_lower
.currency
: is the currency for which the number is formatted. For available currencies seeCldr.Currency.known_currencies/0
. This option is required if:format
is set to:currency
. Ifcurrency
is set and no:format
is set,:format
will be set to:currency
as well.currency_symbol
: Allows overriding a currency symbol. The alternatives are::iso
the ISO currency code will be used instead of the default currency symbol.:narrow
uses the narrow symbol defined for the locale. The same narrow symbol can be defined for more than one currency and therefore this should be used with care. If no narrow symbol is defined, the standard symbol is used.:symbol
uses the standard symbol defined in CLDR. A symbol is unique for each currency and can be safely used.- "string" uses
string
as the currency symbol :standard
(the default and recommended) uses the CLDR-defined symbol based upon the currency format for the locale.
:cash
: a boolean which indicates whether a number being formatted as a:currency
is to be considered a cash value or not. Currencies can be rounded differently depending on whether:cash
istrue
orfalse
. *This option is deprecated in favour ofcurrency_digits: :cash
.:currency_digits
indicates which of the rounding and digits should be used. The options are:accounting
which is the default,:cash
or:iso
:rounding_mode
: determines how a number is rounded to meet the precision of the format requested. The available rounding modes are:down
, :half_up, :half_even, :ceiling, :floor, :half_down, :up. The default is:half_even
.:number_system
: determines which of the number systems for a locale should be used to define the separators and digits for the formatted number. Ifnumber_system
is anatom
thennumber_system
is interpreted as a number system. SeeCldr.Number.System.number_systems_for/2
. If the:number_system
isbinary
then it is interpreted as a number system name. SeeCldr.Number.System.number_system_names_for/2
. The default is:default
.:locale
: determines the locale in which the number is formatted. SeeCldr.known_locale_names/0
. The default isCldr.get_locale/0
which is the locale currently in affect for thisProcess
and which is set byCldr.put_locale/1
.If
:fractional_digits
is set to a positive integer value then the number will be rounded to that number of digits and displayed accordingly - overriding settings that would be applied by default. For example, currencies have fractional digits defined reflecting each currencies minor unit. Setting:fractional_digits
will override that setting.If
:maximum_integer_digits
is set to a positive integer value then the numnber is left truncated before formatting. For example if the number1234
is formatted with the optionmaximum_integer_digits: 2
, the number is truncated to34
and formatted.If
:round_nearest
is set to a positive integer value then the number will be rounded to nearest increment of that value - overriding settings that would be applied by default.:minimum_grouping_digits
overrides the CLDR definition of minimum grouping digits. For example in the localees
the number1234
is formatted by default as1345
because the locale defines theminimium_grouping_digits
as2
. Ifminimum_grouping_digits: 1
is set as an option the number is formatting as1.345
. The:minimum_grouping_digits
is added to the grouping defined by the number format. If the sum of these two digits is greater than the number of digits in the integer (or fractional) part of the number then no grouping is performed.
Locale extensions affecting formatting
A locale identifier can specify options that affect number formatting. These options are:
cu
: defines what currency is implied when no curreny is specified in the call toto_string/2
.cf
: defines whether to use currency or accounting format for formatting currencies. This overrides theformat: :currency
andformat: :accounting
options.nu
: defines the number system to be used if none is specified by the:number_system
option toto_string/2
These keys are part of the u extension and that document should be consulted for details on how to construct a locale identifier with these extensions.
Returns
{:ok, string}
or{:error, {exception, message}}
Examples
iex> Cldr.Number.to_string 12345, TestBackend.Cldr
{:ok, "12,345"}
iex> Cldr.Number.to_string 12345, TestBackend.Cldr, locale: "fr"
{:ok, "12 345"}
iex> Cldr.Number.to_string 1345.32, TestBackend.Cldr, currency: :EUR, locale: "es", minimum_grouping_digits: 1
{:ok, "1.345,32 €"}
iex> Cldr.Number.to_string 1345.32, TestBackend.Cldr, currency: :EUR, locale: "es"
{:ok, "1345,32 €"}
iex> Cldr.Number.to_string 12345, TestBackend.Cldr, locale: "fr", currency: "USD"
{:ok, "12 345,00 $US"}
iex> Cldr.Number.to_string 12345, TestBackend.Cldr, format: "#E0"
{:ok, "1.2345E4"}
iex> Cldr.Number.to_string 12345, TestBackend.Cldr, format: :accounting, currency: "THB"
{:ok, "THB 12,345.00"}
iex> Cldr.Number.to_string -12345, TestBackend.Cldr, format: :accounting, currency: "THB"
{:ok, "(THB 12,345.00)"}
iex> Cldr.Number.to_string 12345, TestBackend.Cldr, format: :accounting, currency: "THB",
...> locale: "th"
{:ok, "฿12,345.00"}
iex> Cldr.Number.to_string 12345, TestBackend.Cldr, format: :accounting, currency: "THB",
...> locale: "th", number_system: :native
{:ok, "฿๑๒,๓๔๕.๐๐"}
iex> Cldr.Number.to_string 1244.30, TestBackend.Cldr, format: :long
{:ok, "1 thousand"}
iex> Cldr.Number.to_string 1244.30, TestBackend.Cldr, format: :long, currency: "USD"
{:ok, "1,244 US dollars"}
iex> Cldr.Number.to_string 1244.30, TestBackend.Cldr, format: :short
{:ok, "1K"}
iex> Cldr.Number.to_string 1244.30, TestBackend.Cldr, format: :short, currency: "EUR"
{:ok, "€1K"}
iex> Cldr.Number.to_string 1234, TestBackend.Cldr, format: :spellout
{:ok, "one thousand two hundred thirty-four"}
iex> Cldr.Number.to_string 1234, TestBackend.Cldr, format: :spellout_verbose
{:ok, "one thousand two hundred and thirty-four"}
iex> Cldr.Number.to_string 1989, TestBackend.Cldr, format: :spellout_year
{:ok, "nineteen eighty-nine"}
iex> Cldr.Number.to_string 123, TestBackend.Cldr, format: :ordinal
{:ok, "123rd"}
iex> Cldr.Number.to_string 123, TestBackend.Cldr, format: :roman
{:ok, "CXXIII"}
iex> Cldr.Number.to_string 123, TestBackend.Cldr, locale: "th-u-nu-thai"
{:ok, "๑๒๓"}
iex> Cldr.Number.to_string 123, TestBackend.Cldr, format: :currency, locale: "en-u-cu-thb"
{:ok, "THB 123.00"}
Errors
An error tuple {:error, reason}
will be returned if an error is detected.
The two most likely causes of an error return are:
- A format cannot be compiled. In this case the error tuple will look like:
iex> Cldr.Number.to_string(12345, TestBackend.Cldr, format: "0#")
{:error, {Cldr.FormatCompileError,
"Decimal format compiler: syntax error before: \"#\""}}
- The format style requested is not defined for the
locale
andnumber_system
. This happens typically when the number system is:algorithmic
rather than the more common:numeric
. In this case the error return looks like:
iex> Cldr.Number.to_string(1234, TestBackend.Cldr, locale: "he", number_system: "hebr")
{:error, {Cldr.UnknownFormatError,
"The locale \"he\" with number system :hebr does not define a format :standard"}}