ICU 62.1  62.1
Data Structures | Namespaces | Typedefs
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/dcfmtsym.h"
#include "unicode/currunit.h"
#include "unicode/fieldpos.h"
#include "unicode/fpositer.h"
#include "unicode/measunit.h"
#include "unicode/nounit.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
 
typedef Notation icu::number::SimpleNotation
 
typedef Precision icu::number::SignificantDigitsPrecision
 
typedef Precision icu::number::Rounder
 
typedef FractionPrecision icu::number::FractionRounder
 
typedef IncrementPrecision icu::number::IncrementRounder
 
typedef CurrencyPrecision icu::number::CurrencyRounder
 

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 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 but without setting a locale until the call site:
static const UnlocalizedNumberFormatter template = NumberFormatter::with()
    .sign(UNumberSignDisplay::UNUM_SIGN_ALWAYS)
    .adoptUnit(MeasureUnit::createMeter(status))
    .unitWidth(UNumberUnitWidth::UNUM_UNIT_WIDTH_FULL_NAME);
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 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

◆ 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 116 of file numberformatter.h.