ICU 74.2: icu::ChoiceFormat Class Reference

ICU 74.2 74.2

Public Member Functions | Static Public Member Functions | Friends
icu::ChoiceFormat Class Reference

ChoiceFormat converts between ranges of numeric values and strings for those ranges. More...

`#include <choicfmt.h>`

Inheritance diagram for icu::ChoiceFormat:

## Public Member Functions
| ChoiceFormat (const UnicodeString &pattern, UErrorCode &status)
| Constructs a new ChoiceFormat from the pattern string.
| ChoiceFormat (const double *limits, const UnicodeString *formats, int32_t count)
| Constructs a new ChoiceFormat with the given limits and message strings.
| ChoiceFormat (const double *limits, const UBool *closures, const UnicodeString *formats, int32_t count)
| Constructs a new ChoiceFormat with the given limits, closure flags and message strings.
| ChoiceFormat (const ChoiceFormat &that)
| Copy constructor.
const ChoiceFormat & | operator= (const ChoiceFormat &that)
| Assignment operator.
virtual | ~ChoiceFormat ()
| Destructor.
virtual ChoiceFormat * | clone () const override
| Clones this Format object.
virtual bool | operator== (const Format &other) const override
| Returns true if the given Format objects are semantically equal.
virtual void | applyPattern (const UnicodeString &pattern, UErrorCode &status)
| Sets the pattern.
virtual void | applyPattern (const UnicodeString &pattern, UParseError &parseError, UErrorCode &status)
| Sets the pattern.
virtual UnicodeString & | toPattern (UnicodeString &pattern) const
| Gets the pattern.
virtual void | setChoices (const double *limitsToCopy, const UnicodeString *formatsToCopy, int32_t count)
| Sets the choices to be used in formatting.
virtual void | setChoices (const double *limits, const UBool *closures, const UnicodeString *formats, int32_t count)
| Sets the choices to be used in formatting.
virtual const double * | getLimits (int32_t &count) const
| Returns nullptr and 0.
virtual const UBool * | getClosures (int32_t &count) const
| Returns nullptr and 0.
virtual const UnicodeString * | getFormats (int32_t &count) const
| Returns nullptr and 0.
virtual UnicodeString & | format (double number, UnicodeString &appendTo, FieldPosition &pos) const override
| Formats a double number using this object's choices.
virtual UnicodeString & | format (int32_t number, UnicodeString &appendTo, FieldPosition &pos) const override
| Formats an int32_t number using this object's choices.
virtual UnicodeString & | format (int64_t number, UnicodeString &appendTo, FieldPosition &pos) const override
| Formats an int64_t number using this object's choices.
virtual UnicodeString & | format (const Formattable *objs, int32_t cnt, UnicodeString &appendTo, FieldPosition &pos, UErrorCode &success) const
| Formats an array of objects using this object's choices.
virtual void | parse (const UnicodeString &text, Formattable &result, ParsePosition &parsePosition) const override
| Looks for the longest match of any message string on the input text and, if there is a match, sets the result object to the corresponding range's number.
virtual UClassID | getDynamicClassID (void) const override
| Returns a unique class ID POLYMORPHICALLY.
virtual UnicodeString & | format (const Formattable &obj, UnicodeString &appendTo, FieldPosition &pos, UErrorCode &status) const override
| Format an object to produce a string.
virtual UnicodeString & | format (const Formattable &obj, UnicodeString &appendTo, FieldPositionIterator *posIter, UErrorCode &status) const override
| Format an object to produce a string.
UnicodeString & | format (double number, UnicodeString &appendTo) const
| Format a double number.
UnicodeString & | format (int32_t number, UnicodeString &appendTo) const
| Format a long number.
UnicodeString & | format (int64_t number, UnicodeString &appendTo) const
| Format an int64 number.
virtual UnicodeString & | format (double number, UnicodeString &appendTo, FieldPosition &pos) const=0
| Format a double number.
virtual UnicodeString & | format (double number, UnicodeString &appendTo, FieldPosition &pos, UErrorCode &status) const
| Format a double number.
virtual UnicodeString & | format (double number, UnicodeString &appendTo, FieldPositionIterator *posIter, UErrorCode &status) const
| Format a double number.
virtual UnicodeString & | format (int32_t number, UnicodeString &appendTo, FieldPosition &pos) const=0
| Format a long number.
virtual UnicodeString & | format (int32_t number, UnicodeString &appendTo, FieldPosition &pos, UErrorCode &status) const
| Format a long number.
virtual UnicodeString & | format (int32_t number, UnicodeString &appendTo, FieldPositionIterator *posIter, UErrorCode &status) const
| Format an int32 number.
virtual UnicodeString & | format (int64_t number, UnicodeString &appendTo, FieldPosition &pos) const
| Format an int64 number.
virtual UnicodeString & | format (int64_t number, UnicodeString &appendTo, FieldPosition &pos, UErrorCode &status) const
| Format an int64 number.
virtual UnicodeString & | format (int64_t number, UnicodeString &appendTo, FieldPositionIterator *posIter, UErrorCode &status) const
| Format an int64 number.
virtual UnicodeString & | format (StringPiece number, UnicodeString &appendTo, FieldPositionIterator *posIter, UErrorCode &status) const
| Format a decimal number.
virtual UnicodeString & | format (const number::impl::DecimalQuantity &number, UnicodeString &appendTo, FieldPositionIterator *posIter, UErrorCode &status) const
| Format a decimal number.
virtual UnicodeString & | format (const number::impl::DecimalQuantity &number, UnicodeString &appendTo, FieldPosition &pos, UErrorCode &status) const
| Format a decimal number.
virtual void | parse (const UnicodeString &text, Formattable &result, ParsePosition &parsePosition) const=0
| Return a long if possible (e.g.
virtual void | parse (const UnicodeString &text, Formattable &result, UErrorCode &status) const
| Parse a string as a numeric value, and return a Formattable numeric object.
Public Member Functions inherited from icu::NumberFormat
virtual | ~NumberFormat ()
| Destructor.
virtual NumberFormat * | clone () const override=0
| Clones this object polymorphically.
virtual bool | operator== (const Format &other) const override
| Return true if the given Format objects are semantically equal.
virtual UnicodeString & | format (const Formattable &obj, UnicodeString &appendTo, FieldPosition &pos, UErrorCode &status) const override
| Format an object to produce a string.
virtual UnicodeString & | format (const Formattable &obj, UnicodeString &appendTo, FieldPositionIterator *posIter, UErrorCode &status) const override
| Format an object to produce a string.
virtual void | parseObject (const UnicodeString &source, Formattable &result, ParsePosition &parse_pos) const override
| Parse a string to produce an object.
UnicodeString & | format (double number, UnicodeString &appendTo) const
| Format a double number.
UnicodeString & | format (int32_t number, UnicodeString &appendTo) const
| Format a long number.
UnicodeString & | format (int64_t number, UnicodeString &appendTo) const
| Format an int64 number.
virtual UnicodeString & | format (double number, UnicodeString &appendTo, FieldPosition &pos) const =0
| Format a double number.
virtual UnicodeString & | format (double number, UnicodeString &appendTo, FieldPosition &pos, UErrorCode &status) const
| Format a double number.
virtual UnicodeString & | format (double number, UnicodeString &appendTo, FieldPositionIterator *posIter, UErrorCode &status) const
| Format a double number.
virtual UnicodeString & | format (int32_t number, UnicodeString &appendTo, FieldPosition &pos) const =0
| Format a long number.
virtual UnicodeString & | format (int32_t number, UnicodeString &appendTo, FieldPosition &pos, UErrorCode &status) const
| Format a long number.
virtual UnicodeString & | format (int32_t number, UnicodeString &appendTo, FieldPositionIterator *posIter, UErrorCode &status) const
| Format an int32 number.
virtual UnicodeString & | format (int64_t number, UnicodeString &appendTo, FieldPosition &pos) const
| Format an int64 number.
virtual UnicodeString & | format (int64_t number, UnicodeString &appendTo, FieldPosition &pos, UErrorCode &status) const
| Format an int64 number.
virtual UnicodeString & | format (int64_t number, UnicodeString &appendTo, FieldPositionIterator *posIter, UErrorCode &status) const
| Format an int64 number.
virtual UnicodeString & | format (StringPiece number, UnicodeString &appendTo, FieldPositionIterator *posIter, UErrorCode &status) const
| Format a decimal number.
virtual UnicodeString & | format (const number::impl::DecimalQuantity &number, UnicodeString &appendTo, FieldPositionIterator *posIter, UErrorCode &status) const
| Format a decimal number.
virtual UnicodeString & | format (const number::impl::DecimalQuantity &number, UnicodeString &appendTo, FieldPosition &pos, UErrorCode &status) const
| Format a decimal number.
virtual void | parse (const UnicodeString &text, Formattable &result, ParsePosition &parsePosition) const =0
| Return a long if possible (e.g.
virtual void | parse (const UnicodeString &text, Formattable &result, UErrorCode &status) const
| Parse a string as a numeric value, and return a Formattable numeric object.
virtual CurrencyAmount * | parseCurrency (const UnicodeString &text, ParsePosition &pos) const
| Parses text from the given string as a currency amount.
UBool | isParseIntegerOnly (void) const
| Return true if this format will parse numbers as integers only.
virtual void | setParseIntegerOnly (UBool value)
| Sets whether or not numbers should be parsed as integers only.
virtual void | setLenient (UBool enable)
| Sets whether lenient parsing should be enabled (it is off by default).
virtual UBool | isLenient (void) const
| Returns whether lenient parsing is enabled (it is off by default).
UBool | isGroupingUsed (void) const
| Returns true if grouping is used in this format.
virtual void | setGroupingUsed (UBool newValue)
| Set whether or not grouping will be used in this format.
int32_t | getMaximumIntegerDigits (void) const
| Returns the maximum number of digits allowed in the integer portion of a number.
virtual void | setMaximumIntegerDigits (int32_t newValue)
| Sets the maximum number of digits allowed in the integer portion of a number.
int32_t | getMinimumIntegerDigits (void) const
| Returns the minimum number of digits allowed in the integer portion of a number.
virtual void | setMinimumIntegerDigits (int32_t newValue)
| Sets the minimum number of digits allowed in the integer portion of a number.
int32_t | getMaximumFractionDigits (void) const
| Returns the maximum number of digits allowed in the fraction portion of a number.
virtual void | setMaximumFractionDigits (int32_t newValue)
| Sets the maximum number of digits allowed in the fraction portion of a number.
int32_t | getMinimumFractionDigits (void) const
| Returns the minimum number of digits allowed in the fraction portion of a number.
virtual void | setMinimumFractionDigits (int32_t newValue)
| Sets the minimum number of digits allowed in the fraction portion of a number.
virtual void | setCurrency (const char16_t *theCurrency, UErrorCode &ec)
| Sets the currency used to display currency amounts.
const char16_t * | getCurrency () const
| Gets the currency used to display currency amounts.
virtual void | setContext (UDisplayContext value, UErrorCode &status)
| Set a particular UDisplayContext value in the formatter, such as UDISPCTX_CAPITALIZATION_FOR_STANDALONE.
virtual UDisplayContext | getContext (UDisplayContextType type, UErrorCode &status) const
| Get the formatter's UDisplayContext value for the specified UDisplayContextType, such as UDISPCTX_TYPE_CAPITALIZATION.
virtual ERoundingMode | getRoundingMode (void) const
| Get the rounding mode.
virtual void | setRoundingMode (ERoundingMode roundingMode)
| Set the rounding mode.
virtual UClassID | getDynamicClassID (void) const override=0
| Returns a unique class ID POLYMORPHICALLY.
UnicodeString & | format (const Formattable &obj, UnicodeString &appendTo, UErrorCode &status) const
| Formats an object to produce a string.
virtual UnicodeString & | format (const Formattable &obj, UnicodeString &appendTo, FieldPosition &pos, UErrorCode &status) const=0
| Format an object to produce a string.
virtual UnicodeString & | format (const Formattable &obj, UnicodeString &appendTo, FieldPositionIterator *posIter, UErrorCode &status) const
| Format an object to produce a string.
Public Member Functions inherited from icu::Format
virtual | ~Format ()
| Destructor.
virtual bool | operator== (const Format &other) const =0
| Return true if the given Format objects are semantically equal.
bool | operator!= (const Format &other) const
| Return true if the given Format objects are not semantically equal.
virtual Format * | clone () const =0
| Clone this object polymorphically.
UnicodeString & | format (const Formattable &obj, UnicodeString &appendTo, UErrorCode &status) const
| Formats an object to produce a string.
virtual UnicodeString & | format (const Formattable &obj, UnicodeString &appendTo, FieldPosition &pos, UErrorCode &status) const =0
| Format an object to produce a string.
virtual UnicodeString & | format (const Formattable &obj, UnicodeString &appendTo, FieldPositionIterator *posIter, UErrorCode &status) const
| Format an object to produce a string.
virtual void | parseObject (const UnicodeString &source, Formattable &result, ParsePosition &parse_pos) const =0
| Parse a string to produce an object.
void | parseObject (const UnicodeString &source, Formattable &result, UErrorCode &status) const
| Parses a string to produce an object.
Locale | getLocale (ULocDataLocaleType type, UErrorCode &status) const
| Get the locale for this format object.
const char * | getLocaleID (ULocDataLocaleType type, UErrorCode &status) const
| Get the locale for this format object.
Public Member Functions inherited from icu::UObject
virtual | ~UObject ()
| Destructor.
virtual UClassID | getDynamicClassID () const
| ICU4C "poor man's RTTI", returns a UClassID for the actual ICU class.

## Static Public Member Functions
static UClassID | getStaticClassID (void)
| Returns the class ID for this class.
Static Public Member Functions inherited from icu::NumberFormat
static NumberFormat * | createInstance (UErrorCode &)
| Create a default style NumberFormat for the current default locale.
static NumberFormat * | createInstance (const Locale &inLocale, UErrorCode &)
| Create a default style NumberFormat for the specified locale.
static NumberFormat * | createInstance (const Locale &desiredLocale, UNumberFormatStyle style, UErrorCode &errorCode)
| Create a specific style NumberFormat for the specified locale.
static NumberFormat * | internalCreateInstance (const Locale &desiredLocale, UNumberFormatStyle style, UErrorCode &errorCode)
| ICU use only.
static const SharedNumberFormat * | createSharedInstance (const Locale &inLocale, UNumberFormatStyle style, UErrorCode &status)
| ICU use only.
static NumberFormat * | createCurrencyInstance (UErrorCode &)
| Returns a currency format for the current default locale.
static NumberFormat * | createCurrencyInstance (const Locale &inLocale, UErrorCode &)
| Returns a currency format for the specified locale.
static NumberFormat * | createPercentInstance (UErrorCode &)
| Returns a percentage format for the current default locale.
static NumberFormat * | createPercentInstance (const Locale &inLocale, UErrorCode &)
| Returns a percentage format for the specified locale.
static NumberFormat * | createScientificInstance (UErrorCode &)
| Returns a scientific format for the current default locale.
static NumberFormat * | createScientificInstance (const Locale &inLocale, UErrorCode &)
| Returns a scientific format for the specified locale.
static const Locale * | getAvailableLocales (int32_t &count)
| Get the set of Locales for which NumberFormats are installed.
static URegistryKey | registerFactory (NumberFormatFactory *toAdopt, UErrorCode &status)
| Register a new NumberFormatFactory.
static UBool | unregister (URegistryKey key, UErrorCode &status)
| Unregister a previously-registered NumberFormatFactory using the key returned from the register call.
static StringEnumeration * | getAvailableLocales (void)
| Return a StringEnumeration over the locales available at the time of the call, including registered locales.
static UClassID | getStaticClassID (void)
| Return the class ID for this class.

## Friends
class | MessageFormat

## Additional Inherited Members
Public Types inherited from icu::NumberFormat
enum | ERoundingMode { kRoundCeiling , kRoundFloor , kRoundDown , kRoundUp , kRoundHalfEven , kRoundHalfDown , kRoundHalfUp , kRoundUnnecessary , kRoundHalfOdd , kRoundHalfCeiling , kRoundHalfFloor }
| Rounding mode. More...
enum | EAlignmentFields { kIntegerField = UNUM_INTEGER_FIELD , kFractionField = UNUM_FRACTION_FIELD , kDecimalSeparatorField = UNUM_DECIMAL_SEPARATOR_FIELD , kExponentSymbolField = UNUM_EXPONENT_SYMBOL_FIELD , kExponentSignField = UNUM_EXPONENT_SIGN_FIELD , kExponentField = UNUM_EXPONENT_FIELD , kGroupingSeparatorField = UNUM_GROUPING_SEPARATOR_FIELD , kCurrencyField = UNUM_CURRENCY_FIELD , kPercentField = UNUM_PERCENT_FIELD , kPermillField = UNUM_PERMILL_FIELD , kSignField = UNUM_SIGN_FIELD , kMeasureUnitField = UNUM_MEASURE_UNIT_FIELD , kCompactField = UNUM_COMPACT_FIELD , INTEGER_FIELD = UNUM_INTEGER_FIELD , FRACTION_FIELD = UNUM_FRACTION_FIELD }
| Alignment Field constants used to construct a FieldPosition object. More...
Protected Member Functions inherited from icu::NumberFormat
| NumberFormat ()
| Default constructor for subclass use only.
| NumberFormat (const NumberFormat &)
| Copy constructor.
NumberFormat & | operator= (const NumberFormat &)
| Assignment operator.
virtual void | getEffectiveCurrency (char16_t *result, UErrorCode &ec) const
| Returns the currency in effect for this formatter.
Protected Member Functions inherited from icu::Format
void | setLocaleIDs (const char *valid, const char *actual)
| Format ()
| Default constructor for subclass use only.
| Format (const Format &)
Format & | operator= (const Format &)
Static Protected Member Functions inherited from icu::NumberFormat
static NumberFormat * | makeInstance (const Locale &desiredLocale, UNumberFormatStyle style, UBool mustBeDecimalFormat, UErrorCode &errorCode)
| Creates the specified number format style of the desired locale.
Static Protected Member Functions inherited from icu::Format
static void | syntaxError (const UnicodeString &pattern, int32_t pos, UParseError &parseError)
| Simple function for initializing a UParseError from a UnicodeString.
Static Protected Attributes inherited from icu::NumberFormat
static const int32_t | gDefaultMaxIntegerDigits
static const int32_t | gDefaultMinIntegerDigits

## Detailed Description

ChoiceFormat converts between ranges of numeric values and strings for those ranges.

The strings must conform to the MessageFormat pattern syntax.

`ChoiceFormat` is probably not what you need. Please use `MessageFormat` with `plural` arguments for proper plural selection, and `select` arguments for simple selection among a fixed set of choices!

A `ChoiceFormat` splits the real number line `-∞` to `+∞` into two or more contiguous ranges. Each range is mapped to a string.

`ChoiceFormat` was originally intended for displaying grammatically correct plurals such as "There is one file." vs. "There are 2 files." However, plural rules for many languages are too complex for the capabilities of ChoiceFormat, and its requirement of specifying the precise rules for each message is unmanageable for translators.

There are two methods of defining a `ChoiceFormat`; both are equivalent. The first is by using a string pattern. This is the preferred method in most cases. The second method is through direct specification of the arrays that logically make up the `ChoiceFormat`.

Note: Typically, choice formatting is done (if done at all) via `MessageFormat` with a `choice` argument type, rather than using a stand-alone `ChoiceFormat`.

##### Patterns and Their Interpretation

The pattern string defines the range boundaries and the strings for each number range. Syntax:

    choiceStyle = number separator message ('|' number separator message)*
    number = normal_number | ['-']  ∞ (U+221E, infinity)
    normal_number = double value (unlocalized ASCII string)
    separator = less_than | less_than_or_equal
    less_than = '<'
    less_than_or_equal = '#' |  ≤ (U+2264)
    message: see MessageFormat

Pattern_White_Space between syntax elements is ignored, except around each range's sub-message.

Each numeric sub-range extends from the current range's number to the next range's number. The number itself is included in its range if a `less_than_or_equal` sign is used, and excluded from its range (and instead included in the previous range) if a `less_than` sign is used.

When a `ChoiceFormat` is constructed from arrays of numbers, closure flags and strings, they are interpreted just like the sequence of `(number separator string)` in an equivalent pattern string. `closure[i]==true` corresponds to a `less_than` separator sign. The equivalent pattern string will be constructed automatically.

During formatting, a number is mapped to the first range where the number is not greater than the range's upper limit. That range's message string is returned. A NaN maps to the very first range.

During parsing, a range is selected for the longest match of any range's message. That range's number is returned, ignoring the separator/closure. Only a simple string match is performed, without parsing of arguments that might be specified in the message strings.

Note that the first range's number is ignored in formatting but may be returned from parsing.

##### Examples

Here is an example of two arrays that map the number `1..7` to the English day of the week abbreviations `Sun..Sat`. No closures array is given; this is the same as specifying all closures to be `false`.

        {1,2,3,4,5,6,7},
        {"Sun","Mon","Tue","Wed","Thur","Fri","Sat"}

Here is an example that maps the ranges [-Inf, 1), [1, 1], and (1, +Inf] to three strings. That is, the number line is split into three ranges: x < 1.0, x = 1.0, and x > 1.0. (The round parentheses in the notation above indicate an exclusive boundary, like the turned bracket in European notation: [-Inf, 1) == [-Inf, 1[ )

        {0, 1, 1},
        {false, false, true},
        {"no files", "one file", "many files"}

Here is an example that shows formatting and parsing:

#include <unicode/choicfmt.h>
#include <unicode/unistr.h>
#include <iostream.h>
int main(int argc, char *argv[]) {
double limits[] = {1,2,3,4,5,6,7};
UnicodeString monthNames[] = {
"Sun","Mon","Tue","Wed","Thu","Fri","Sat"};
ChoiceFormat fmt(limits, monthNames, 7);
UnicodeString str;
char buf[256];
for (double x = 1.0; x <= 8.0; x += 1.0) {
fmt.format(x, str);
str.extract(0, str.length(), buf, 256, "");
str.truncate(0);
cout << x << " -> "
<< buf << endl;
}
cout << endl;
return 0;
}
choicfmt.h
C++ API: Choice Format.
icu::UnicodeString
UnicodeString is a string class that stores Unicode characters directly and provides similar function...
Definition unistr.h:296
unistr.h
C++ API: Unicode String.

User subclasses are not supported. While clients may write subclasses, such code will not necessarily work and will not be guaranteed to work stably from release to release.

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

Definition at line 176 of file choicfmt.h.

## Constructor & Destructor Documentation

## ◆ ChoiceFormat() [1/4]

icu::ChoiceFormat::ChoiceFormat | ( | const UnicodeString & | pattern,
|  | UErrorCode & | status
| ) |  |

Constructs a new ChoiceFormat from the pattern string.

Parameters

  pattern | Pattern used to construct object.
  status | Output param to receive success code. If the pattern cannot be parsed, set to failure code.

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

## ◆ ChoiceFormat() [2/4]

icu::ChoiceFormat::ChoiceFormat | ( | const double * | limits,
|  | const UnicodeString * | formats,
|  | int32_t | count
| ) |  |

Constructs a new ChoiceFormat with the given limits and message strings.

All closure flags default to `false`, equivalent to `less_than_or_equal` separators.

Copies the limits and formats instead of adopting them.

Parameters

  limits | Array of limit values.
  formats | Array of formats.
  count | Size of 'limits' and 'formats' arrays.

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

## ◆ ChoiceFormat() [3/4]

icu::ChoiceFormat::ChoiceFormat | ( | const double * | limits,
|  | const UBool * | closures,
|  | const UnicodeString * | formats,
|  | int32_t | count
| ) |  |

Constructs a new ChoiceFormat with the given limits, closure flags and message strings.

Copies the limits and formats instead of adopting them.

Parameters

  limits | Array of limit values
  closures | Array of booleans specifying whether each element of 'limits' is open or closed. If false, then the corresponding limit number is a member of its range. If true, then the limit number belongs to the previous range it.
  formats | Array of formats
  count | Size of 'limits', 'closures', and 'formats' arrays

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

## ◆ ChoiceFormat() [4/4]

icu::ChoiceFormat::ChoiceFormat | ( | const ChoiceFormat & | that | ) |

Copy constructor.

Parameters

  that | ChoiceFormat object to be copied from

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

## ◆ ~ChoiceFormat()

virtual icu::ChoiceFormat::~ChoiceFormat | ( |  | ) |
| virtual

Destructor.

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

## Member Function Documentation

## ◆ applyPattern() [1/2]

virtual void icu::ChoiceFormat::applyPattern | ( | const UnicodeString & | pattern,
|  | UErrorCode & | status
| ) |  |
| virtual

Sets the pattern.

Parameters

  pattern | The pattern to be applied.
  status | Output param set to success/failure code on exit. If the pattern is invalid, this will be set to a failure result.

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

## ◆ applyPattern() [2/2]

virtual void icu::ChoiceFormat::applyPattern | ( | const UnicodeString & | pattern,
|  | UParseError & | parseError,
|  | UErrorCode & | status
| ) |  |
| virtual

Sets the pattern.

Parameters

  pattern | The pattern to be applied.
  parseError | Struct to receive information on position of error if an error is encountered
  status | Output param set to success/failure code on exit. If the pattern is invalid, this will be set to a failure result.

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

## ◆ clone()

virtual ChoiceFormat * icu::ChoiceFormat::clone | ( |  | ) | const
| overridevirtual

Clones this Format object.

The caller owns the result and must delete it when done.

Returns
  a copy of this object

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

Implements icu::NumberFormat.

## ◆ format() [1/21]

virtual UnicodeString & icu::NumberFormat::format | ( | const Formattable & | obj,
|  | UnicodeString & | appendTo,
|  | FieldPosition & | pos,
|  | UErrorCode & | status
| ) |  | const
| overridevirtual

Format an object to produce a string.

This method handles Formattable objects with numeric types. If the Formattable object type is not a numeric type, then it returns a failing UErrorCode.

Parameters

  obj | The object to format.
  appendTo | Output parameter to receive result. Result is appended to existing contents.
  pos | On input: an alignment field, if desired. On output: the offsets of the alignment field.
  status | Output param filled with success/failure status.

Returns
  Reference to 'appendTo' parameter.

Stable:
  ICU 2.0

Reimplemented from icu::NumberFormat.

## ◆ format() [2/21]

virtual UnicodeString & icu::NumberFormat::format | ( | const Formattable & | obj,
|  | UnicodeString & | appendTo,
|  | FieldPositionIterator * | posIter,
|  | UErrorCode & | status
| ) |  | const
| overridevirtual

Format an object to produce a string.

This method handles Formattable objects with numeric types. If the Formattable object type is not a numeric type, then it returns a failing UErrorCode.

Parameters

  obj | The object to format.
  appendTo | Output parameter to receive result. Result is appended to existing contents.
  posIter | On return, can be used to iterate over positions of fields generated by this format call. Can be nullptr.
  status | Output param filled with success/failure status.

Returns
  Reference to 'appendTo' parameter.

Stable:
  ICU 4.4

Reimplemented from icu::NumberFormat.

## ◆ format() [3/21]

virtual UnicodeString & icu::ChoiceFormat::format | ( | const Formattable * | objs,
|  | int32_t | cnt,
|  | UnicodeString & | appendTo,
|  | FieldPosition & | pos,
|  | UErrorCode & | success
| ) |  | const
| virtual

Formats an array of objects using this object's choices.

Parameters

  objs | The array of objects to be formatted.
  cnt | The size of objs.
  appendTo | Output parameter to receive result. Result is appended to existing contents.
  pos | On input: an alignment field, if desired. On output: the offsets of the alignment field.
  success | Output param set to success/failure code on exit.

Returns
  Reference to 'appendTo' parameter.

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

## ◆ format() [4/21]

virtual UnicodeString & icu::NumberFormat::format | ( | const number::impl::DecimalQuantity & | number,
|  | UnicodeString & | appendTo,
|  | FieldPosition & | pos,
|  | UErrorCode & | status
| ) |  | const
| virtual

Format a decimal number.

The number is a DecimalQuantity wrapper onto a floating point decimal number. The default implementation in NumberFormat converts the decimal number to a double and formats that. Subclasses of NumberFormat that want to specifically handle big decimal numbers must override this method. class DecimalFormat does so.

Parameters

  number | The number, a DecimalQuantity format Decimal Floating Point.
  appendTo | Output parameter to receive result. Result is appended to existing contents.
  pos | On input: an alignment field, if desired. On output: the offsets of the alignment field.
  status | Output param filled with success/failure status.

Returns
  Reference to 'appendTo' parameter.

Internal:
  Do not use. This API is for internal use only.

Reimplemented from icu::NumberFormat.

## ◆ format() [5/21]

virtual UnicodeString & icu::NumberFormat::format | ( | const number::impl::DecimalQuantity & | number,
|  | UnicodeString & | appendTo,
|  | FieldPositionIterator * | posIter,
|  | UErrorCode & | status
| ) |  | const
| virtual

Format a decimal number.

The number is a DecimalQuantity wrapper onto a floating point decimal number. The default implementation in NumberFormat converts the decimal number to a double and formats that. Subclasses of NumberFormat that want to specifically handle big decimal numbers must override this method. class DecimalFormat does so.

Parameters

  number | The number, a DecimalQuantity format Decimal Floating Point.
  appendTo | Output parameter to receive result. Result is appended to existing contents.
  posIter | On return, can be used to iterate over positions of fields generated by this format call.
  status | Output param filled with success/failure status.

Returns
  Reference to 'appendTo' parameter.

Internal:
  Do not use. This API is for internal use only.

Reimplemented from icu::NumberFormat.

## ◆ format() [6/21]

UnicodeString & icu::NumberFormat::format | ( | double | number,
|  | UnicodeString & | appendTo
| ) |  | const

Format a double number.

These methods call the NumberFormat pure virtual format() methods with the default FieldPosition.

Parameters

  number | The value to be formatted.
  appendTo | Output parameter to receive result. Result is appended to existing contents.

Returns
  Reference to 'appendTo' parameter.

Stable:
  ICU 2.0

## ◆ format() [7/21]

virtual UnicodeString & icu::ChoiceFormat::format | ( | double | number,
|  | UnicodeString & | appendTo,
|  | FieldPosition & | pos
| ) |  | const
| overridevirtual

Formats a double number using this object's choices.

Parameters

  number | The value to be formatted.
  appendTo | Output parameter to receive result. Result is appended to existing contents.
  pos | On input: an alignment field, if desired. On output: the offsets of the alignment field.

Returns
  Reference to 'appendTo' parameter.

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

Implements icu::NumberFormat.

## ◆ format() [8/21]

virtual UnicodeString & icu::NumberFormat::format | ( | double | number,
|  | UnicodeString & | appendTo,
|  | FieldPosition & | pos
| ) |  | const
| virtual

Format a double number.

Concrete subclasses must implement these pure virtual methods.

Parameters

  number | The value to be formatted.
  appendTo | Output parameter to receive result. Result is appended to existing contents.
  pos | On input: an alignment field, if desired. On output: the offsets of the alignment field.

Returns
  Reference to 'appendTo' parameter.

Stable:
  ICU 2.0

Implements icu::NumberFormat.

## ◆ format() [9/21]

virtual UnicodeString & icu::NumberFormat::format | ( | double | number,
|  | UnicodeString & | appendTo,
|  | FieldPosition & | pos,
|  | UErrorCode & | status
| ) |  | const
| virtual

Format a double number.

By default, the parent function simply calls the base class and does not return an error status. Therefore, the status may be ignored in some subclasses.

Parameters

  number | The value to be formatted.
  appendTo | Output parameter to receive result. Result is appended to existing contents.
  pos | On input: an alignment field, if desired. On output: the offsets of the alignment field.
  status | error status

Returns
  Reference to 'appendTo' parameter.

Internal:
  Do not use. This API is for internal use only.

Reimplemented from icu::NumberFormat.

## ◆ format() [10/21]

virtual UnicodeString & icu::NumberFormat::format | ( | double | number,
|  | UnicodeString & | appendTo,
|  | FieldPositionIterator * | posIter,
|  | UErrorCode & | status
| ) |  | const
| virtual

Format a double number.

Subclasses must implement this method.

Parameters

  number | The value to be formatted.
  appendTo | Output parameter to receive result. Result is appended to existing contents.
  posIter | On return, can be used to iterate over positions of fields generated by this format call. Can be nullptr.
  status | Output param filled with success/failure status.

Returns
  Reference to 'appendTo' parameter.

Stable:
  ICU 4.4

Reimplemented from icu::NumberFormat.

## ◆ format() [11/21]

UnicodeString & icu::NumberFormat::format | ( | int32_t | number,
|  | UnicodeString & | appendTo
| ) |  | const

Format a long number.

These methods call the NumberFormat pure virtual format() methods with the default FieldPosition.

Parameters

  number | The value to be formatted.
  appendTo | Output parameter to receive result. Result is appended to existing contents.

Returns
  Reference to 'appendTo' parameter.

Stable:
  ICU 2.0

## ◆ format() [12/21]

virtual UnicodeString & icu::ChoiceFormat::format | ( | int32_t | number,
|  | UnicodeString & | appendTo,
|  | FieldPosition & | pos
| ) |  | const
| overridevirtual

Formats an int32_t number using this object's choices.

Parameters

  number | The value to be formatted.
  appendTo | Output parameter to receive result. Result is appended to existing contents.
  pos | On input: an alignment field, if desired. On output: the offsets of the alignment field.

Returns
  Reference to 'appendTo' parameter.

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

Implements icu::NumberFormat.

## ◆ format() [13/21]

virtual UnicodeString & icu::NumberFormat::format | ( | int32_t | number,
|  | UnicodeString & | appendTo,
|  | FieldPosition & | pos
| ) |  | const
| virtual

Format a long number.

Concrete subclasses must implement these pure virtual methods.

Parameters

  number | The value to be formatted.
  appendTo | Output parameter to receive result. Result is appended to existing contents.
  pos | On input: an alignment field, if desired. On output: the offsets of the alignment field.

Returns
  Reference to 'appendTo' parameter.

Stable:
  ICU 2.0

Implements icu::NumberFormat.

## ◆ format() [14/21]

virtual UnicodeString & icu::NumberFormat::format | ( | int32_t | number,
|  | UnicodeString & | appendTo,
|  | FieldPosition & | pos,
|  | UErrorCode & | status
| ) |  | const
| virtual

Format a long number.

Concrete subclasses may override this function to provide status return.

Parameters

  number | The value to be formatted.
  appendTo | Output parameter to receive result. Result is appended to existing contents.
  pos | On input: an alignment field, if desired. On output: the offsets of the alignment field.
  status | the output status.

Returns
  Reference to 'appendTo' parameter.

Internal:
  Do not use. This API is for internal use only.

Reimplemented from icu::NumberFormat.

## ◆ format() [15/21]

virtual UnicodeString & icu::NumberFormat::format | ( | int32_t | number,
|  | UnicodeString & | appendTo,
|  | FieldPositionIterator * | posIter,
|  | UErrorCode & | status
| ) |  | const
| virtual

Format an int32 number.

Subclasses must implement this method.

Parameters

  number | The value to be formatted.
  appendTo | Output parameter to receive result. Result is appended to existing contents.
  posIter | On return, can be used to iterate over positions of fields generated by this format call. Can be nullptr.
  status | Output param filled with success/failure status.

Returns
  Reference to 'appendTo' parameter.

Stable:
  ICU 4.4

Reimplemented from icu::NumberFormat.

## ◆ format() [16/21]

UnicodeString & icu::NumberFormat::format | ( | int64_t | number,
|  | UnicodeString & | appendTo
| ) |  | const

Format an int64 number.

These methods call the NumberFormat pure virtual format() methods with the default FieldPosition.

Parameters

  number | The value to be formatted.
  appendTo | Output parameter to receive result. Result is appended to existing contents.

Returns
  Reference to 'appendTo' parameter.

Stable:
  ICU 2.8

## ◆ format() [17/21]

virtual UnicodeString & icu::NumberFormat::format | ( | int64_t | number,
|  | UnicodeString & | appendTo,
|  | FieldPosition & | pos
| ) |  | const
| virtual

Format an int64 number.

(Not abstract to retain compatibility with earlier releases, however subclasses should override this method as it just delegates to format(int32_t number...);

Parameters

  number | The value to be formatted.
  appendTo | Output parameter to receive result. Result is appended to existing contents.
  pos | On input: an alignment field, if desired. On output: the offsets of the alignment field.

Returns
  Reference to 'appendTo' parameter.

Stable:
  ICU 2.8

Reimplemented from icu::NumberFormat.

## ◆ format() [18/21]

virtual UnicodeString & icu::ChoiceFormat::format | ( | int64_t | number,
|  | UnicodeString & | appendTo,
|  | FieldPosition & | pos
| ) |  | const
| overridevirtual

Formats an int64_t number using this object's choices.

Parameters

  number | The value to be formatted.
  appendTo | Output parameter to receive result. Result is appended to existing contents.
  pos | On input: an alignment field, if desired. On output: the offsets of the alignment field.

Returns
  Reference to 'appendTo' parameter.

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

Reimplemented from icu::NumberFormat.

## ◆ format() [19/21]

virtual UnicodeString & icu::NumberFormat::format | ( | int64_t | number,
|  | UnicodeString & | appendTo,
|  | FieldPosition & | pos,
|  | UErrorCode & | status
| ) |  | const
| virtual

Format an int64 number.

(Not abstract to retain compatibility with earlier releases, however subclasses should override this method as it just delegates to format(int32_t number...);

Parameters

  number | The value to be formatted.
  appendTo | Output parameter to receive result. Result is appended to existing contents.
  pos | On input: an alignment field, if desired. On output: the offsets of the alignment field.
  status | Output param filled with success/failure status.

Returns
  Reference to 'appendTo' parameter.

Internal:
  Do not use. This API is for internal use only.

Reimplemented from icu::NumberFormat.

## ◆ format() [20/21]

virtual UnicodeString & icu::NumberFormat::format | ( | int64_t | number,
|  | UnicodeString & | appendTo,
|  | FieldPositionIterator * | posIter,
|  | UErrorCode & | status
| ) |  | const
| virtual

Format an int64 number.

Subclasses must implement this method.

Parameters

  number | The value to be formatted.
  appendTo | Output parameter to receive result. Result is appended to existing contents.
  posIter | On return, can be used to iterate over positions of fields generated by this format call. Can be nullptr.
  status | Output param filled with success/failure status.

Returns
  Reference to 'appendTo' parameter.

Stable:
  ICU 4.4

Reimplemented from icu::NumberFormat.

## ◆ format() [21/21]

virtual UnicodeString & icu::NumberFormat::format | ( | StringPiece | number,
|  | UnicodeString & | appendTo,
|  | FieldPositionIterator * | posIter,
|  | UErrorCode & | status
| ) |  | const
| virtual

Format a decimal number.

Subclasses must implement this method. The syntax of the unformatted number is a "numeric string" as defined in the Decimal Arithmetic Specification, available at http://speleotrove.com/decimal

Parameters

  number | The unformatted number, as a string, to be formatted.
  appendTo | Output parameter to receive result. Result is appended to existing contents.
  posIter | On return, can be used to iterate over positions of fields generated by this format call. Can be nullptr.
  status | Output param filled with success/failure status.

Returns
  Reference to 'appendTo' parameter.

Stable:
  ICU 4.4

Reimplemented from icu::NumberFormat.

## ◆ getClosures()

virtual const UBool * icu::ChoiceFormat::getClosures | ( | int32_t & | count | ) | const
| virtual

Returns nullptr and 0.

Before ICU 4.8, this used to return the limit booleans array.

Parameters

  count | Will be set to 0.

Returns
  nullptr

Deprecated:
  ICU 4.8 Use the MessagePattern class to analyze a ChoiceFormat pattern.

## ◆ getDynamicClassID()

virtual UClassID icu::ChoiceFormat::getDynamicClassID | ( | void |  | ) | const
| overridevirtual

Returns a unique class ID POLYMORPHICALLY.

Part of ICU's "poor man's RTTI".

Returns
  The class ID for this object. All objects of a given class have the same class ID. Objects of other classes have different class IDs.

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

Implements icu::NumberFormat.

## ◆ getFormats()

virtual const UnicodeString * icu::ChoiceFormat::getFormats | ( | int32_t & | count | ) | const
| virtual

Returns nullptr and 0.

Before ICU 4.8, this used to return the array of choice strings.

Parameters

  count | Will be set to 0.

Returns
  nullptr

Deprecated:
  ICU 4.8 Use the MessagePattern class to analyze a ChoiceFormat pattern.

## ◆ getLimits()

virtual const double * icu::ChoiceFormat::getLimits | ( | int32_t & | count | ) | const
| virtual

Returns nullptr and 0.

Before ICU 4.8, this used to return the choice limits array.

Parameters

  count | Will be set to 0.

Returns
  nullptr

Deprecated:
  ICU 4.8 Use the MessagePattern class to analyze a ChoiceFormat pattern.

## ◆ getStaticClassID()

static UClassID icu::ChoiceFormat::getStaticClassID | ( | void |  | ) |
| static

Returns the class ID for this class.

This is useful only for comparing to a return value from getDynamicClassID(). For example:

    .       Base* polymorphic_pointer = createPolymorphicObject();
    .       if (polymorphic_pointer->getDynamicClassID() ==
    .           Derived::getStaticClassID()) ...

Returns
  The class ID for all objects of this class.

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

## ◆ operator=()

const ChoiceFormat & icu::ChoiceFormat::operator= | ( | const ChoiceFormat & | that | ) |

Assignment operator.

Parameters

  that | ChoiceFormat object to be copied

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

## ◆ operator==()

virtual bool icu::ChoiceFormat::operator== | ( | const Format & | other | ) | const
| overridevirtual

Returns true if the given Format objects are semantically equal.

Objects of different subclasses are considered unequal.

Parameters

  other | ChoiceFormat object to be compared

Returns
  true if other is the same as this.

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

Reimplemented from icu::NumberFormat.

## ◆ parse() [1/3]

virtual void icu::ChoiceFormat::parse | ( | const UnicodeString & | text,
|  | Formattable & | result,
|  | ParsePosition & | parsePosition
| ) |  | const
| overridevirtual

Looks for the longest match of any message string on the input text and, if there is a match, sets the result object to the corresponding range's number.

If no string matches, then the parsePosition is unchanged.

Parameters

  text | The text to be parsed.
  result | Formattable to be set to the parse result. If parse fails, return contents are undefined.
  parsePosition | The position to start parsing at on input. On output, moved to after the last successfully parse character. On parse failure, does not change.

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

Implements icu::NumberFormat.

## ◆ parse() [2/3]

virtual void icu::NumberFormat::parse | ( | const UnicodeString & | text,
|  | Formattable & | result,
|  | ParsePosition & | parsePosition
| ) |  | const
| virtual

Return a long if possible (e.g.

within range LONG_MAX, LONG_MAX], and with no decimals), otherwise a double. If IntegerOnly is set, will stop at a decimal point (or equivalent; e.g. for rational numbers "1 2/3", will stop after the 1).

If no object can be parsed, index is unchanged, and nullptr is returned.

This is a pure virtual which concrete subclasses must implement.

Parameters

  text | The text to be parsed.
  result | Formattable to be set to the parse result. If parse fails, return contents are undefined.
  parsePosition | The position to start parsing at on input. On output, moved to after the last successfully parse character. On parse failure, does not change.

Stable:
  ICU 2.0

Implements icu::NumberFormat.

## ◆ parse() [3/3]

virtual void icu::NumberFormat::parse | ( | const UnicodeString & | text,
|  | Formattable & | result,
|  | UErrorCode & | status
| ) |  | const
| virtual

Parse a string as a numeric value, and return a Formattable numeric object.

This method parses integers only if IntegerOnly is set.

Parameters

  text | The text to be parsed.
  result | Formattable to be set to the parse result. If parse fails, return contents are undefined.
  status | Output parameter set to a failure error code when a failure occurs. The error code when the string fails to parse is U_INVALID_FORMAT_ERROR, unless overridden by a subclass.

See also
  NumberFormat::isParseIntegerOnly

Stable:
  ICU 2.0

Reimplemented from icu::NumberFormat.

## ◆ setChoices() [1/2]

virtual void icu::ChoiceFormat::setChoices | ( | const double * | limits,
|  | const UBool * | closures,
|  | const UnicodeString * | formats,
|  | int32_t | count
| ) |  |
| virtual

Sets the choices to be used in formatting.

For details see the constructor with the same parameter list.

Parameters

  limits | Array of limits
  closures | Array of limit booleans
  formats | Array of format string
  count | The size of the above arrays

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

## ◆ setChoices() [2/2]

virtual void icu::ChoiceFormat::setChoices | ( | const double * | limitsToCopy,
|  | const UnicodeString * | formatsToCopy,
|  | int32_t | count
| ) |  |
| virtual

Sets the choices to be used in formatting.

For details see the constructor with the same parameter list.

Parameters

  limitsToCopy | Contains the top value that you want parsed with that format,and should be in ascending sorted order. When formatting X, the choice will be the i, where limit[i] <= X < limit[i+1].
  formatsToCopy | The format strings you want to use for each limit.
  count | The size of the above arrays.

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

## ◆ toPattern()

virtual UnicodeString & icu::ChoiceFormat::toPattern | ( | UnicodeString & | pattern | ) | const
| virtual

Gets the pattern.

Parameters

  pattern | Output param which will receive the pattern Previous contents are deleted.

Returns
  A reference to 'pattern'

Deprecated:
  ICU 49 Use MessageFormat instead, with plural and select arguments.

## Friends And Related Symbol Documentation

## ◆ MessageFormat

friend class MessageFormat
| friend

Definition at line 497 of file choicfmt.h.

The documentation for this class was generated from the following file:

- i18n/unicode/choicfmt.h