numberformatter.h File Reference

C++ API: Library for localized number formatting introduced in ICU 60. More...

#include "unicode/utypes.h"
#include "unicode/appendable.h"
#include "unicode/bytestream.h"
#include "unicode/currunit.h"
#include "unicode/dcfmtsym.h"
#include "unicode/fieldpos.h"
#include "unicode/formattedvalue.h"
#include "unicode/fpositer.h"
#include "unicode/measunit.h"
#include "unicode/nounit.h"
#include "unicode/parseerr.h"
#include "unicode/plurrule.h"
#include "unicode/ucurr.h"
#include "unicode/unum.h"
#include "unicode/unumberformatter.h"
#include "unicode/uobject.h"

Go to the source code of this file.

Data Structures
class	icu::number::Notation
	A class that defines the notation style to be used when formatting numbers in NumberFormatter. More...
struct	icu::number::Notation::NotationUnion::ScientificSettings
class	icu::number::ScientificNotation
	A class that defines the scientific notation style to be used when formatting numbers in NumberFormatter. More...
class	icu::number::Precision
	A class that defines the rounding precision to be used when formatting numbers in NumberFormatter. More...
struct	icu::number::Precision::PrecisionUnion::FractionSignificantSettings
struct	icu::number::Precision::PrecisionUnion::IncrementSettings
class	icu::number::FractionPrecision
	A class that defines a rounding precision based on a number of fraction places and optionally significant digits to be used when formatting numbers in NumberFormatter. More...
class	icu::number::CurrencyPrecision
	A class that defines a rounding precision parameterized by a currency to be used when formatting numbers in NumberFormatter. More...
class	icu::number::IncrementPrecision
	A class that defines a rounding precision parameterized by a rounding increment to be used when formatting numbers in NumberFormatter. More...
class	icu::number::IntegerWidth
	A class that defines the strategy for padding and truncating integers before the decimal separator. More...
class	icu::number::Scale
	A class that defines a quantity by which a number should be multiplied when formatting. More...
class	icu::number::impl::SymbolsWrapper
class	icu::number::impl::Grouper
class	icu::number::impl::Padder
struct	icu::number::impl::MacroProps
class	icu::number::NumberFormatterSettings< Derived >
	An abstract base class for specifying settings related to number formatting. More...
class	icu::number::UnlocalizedNumberFormatter
	A NumberFormatter that does not yet have a locale. More...
class	icu::number::LocalizedNumberFormatter
	A NumberFormatter that has a locale associated with it; this means .format() methods are available. More...
class	icu::number::FormattedNumber
	The result of a number formatting operation. More...
class	icu::number::NumberFormatter
	See the main description in numberformatter.h for documentation and examples. More...

Namespaces
	icu
	File coll.h.

Typedefs
typedef int16_t	icu::number::impl::digits_t
	Datatype for minimum/maximum fraction digits. More...
typedef Notation	icu::number::CompactNotation
	Extra name reserved in case it is needed in the future. More...
typedef Notation	icu::number::SimpleNotation
	Extra name reserved in case it is needed in the future. More...
typedef Precision	icu::number::SignificantDigitsPrecision
	Extra name reserved in case it is needed in the future. More...

Functions
void	icu::number::impl::touchRangeLocales (impl::RangeMacroProps &macros)
	Used for NumberRangeFormatter and implemented in numrange_fluent.cpp. More...

Detailed Description

C++ API: Library for localized number formatting introduced in ICU 60.

This library was introduced in ICU 60 to simplify the process of formatting localized number strings. Basic usage examples:

// Most basic usage:
NumberFormatter::withLocale(...).format(123).toString();  // 1,234 in en-US

// Custom notation, unit, and rounding precision:
NumberFormatter::with()
    .notation(Notation::compactShort())
    .unit(CurrencyUnit("EUR", status))
    .precision(Precision::maxDigits(2))
    .locale(...)
    .format(1234)
    .toString();  // €1.2K in en-US

// Create a formatter in a singleton by value for use later:
static const LocalizedNumberFormatter formatter = NumberFormatter::withLocale(...)
    .unit(NoUnit::percent())
    .precision(Precision::fixedFraction(3));
formatter.format(5.9831).toString();  // 5.983% in en-US

// Create a "template" in a singleton unique_ptr but without setting a locale until the call site:
std::unique_ptr<UnlocalizedNumberFormatter> template = NumberFormatter::with()
    .sign(UNumberSignDisplay::UNUM_SIGN_ALWAYS)
    .unit(MeasureUnit::getMeter())
    .unitWidth(UNumberUnitWidth::UNUM_UNIT_WIDTH_FULL_NAME)
    .clone();
template->locale(...).format(1234).toString();  // +1,234 meters in en-US

This API offers more features than DecimalFormat and is geared toward new users of ICU.

NumberFormatter instances (i.e., LocalizedNumberFormatter and UnlocalizedNumberFormatter) are immutable and thread safe. This means that invoking a configuration method has no effect on the receiving instance; you must store and use the new number formatter instance it returns instead.

UnlocalizedNumberFormatter formatter = UnlocalizedNumberFormatter::with().notation(Notation::scientific());
formatter.precision(Precision.maxFraction(2)); // does nothing!
formatter.locale(Locale.getEnglish()).format(9.8765).toString(); // prints "9.8765E0", not "9.88E0"

This API is based on the fluent design pattern popularized by libraries such as Google's Guava. For extensive details on the design of this API, read the design doc.

Author

Shane Carr

Definition in file numberformatter.h.

Typedef Documentation

CompactNotation

typedef Notation icu::number::CompactNotation

Extra name reserved in case it is needed in the future.

Stable:

ICU 63

Definition at line 174 of file numberformatter.h.

digits_t

typedef int16_t icu::number::impl::digits_t

Datatype for minimum/maximum fraction digits.

Must be able to hold kMaxIntFracSig.

Internal:

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

Definition at line 124 of file numberformatter.h.

SignificantDigitsPrecision

typedef Precision icu::number::SignificantDigitsPrecision

Extra name reserved in case it is needed in the future.

Stable:

ICU 63

Definition at line 449 of file numberformatter.h.

SimpleNotation

typedef Notation icu::number::SimpleNotation

Extra name reserved in case it is needed in the future.

Stable:

ICU 63

Definition at line 181 of file numberformatter.h.

Function Documentation

touchRangeLocales()

void icu::number::impl::touchRangeLocales

(

impl::RangeMacroProps &

macros

)

Used for NumberRangeFormatter and implemented in numrange_fluent.cpp.

Declared here so it can be friended.

Internal:

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