NumberFormatter

Kotlin |Java

public final class NumberFormatter
extends Object

java.lang.Object
↳	android.icu.number.NumberFormatter

All-in-one formatter for localized numbers, currencies, and units. For a full list of options, see NumberFormatterSettings.

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

 // Custom notation, unit, and rounding strategy:
 NumberFormatter.with()
     .notation(Notation.compactShort())
     .unit(Currency.getInstance("EUR"))
     .precision(Precision.maxDigits(2))
     .locale(...)
     .format(1234)
     .toString();  // \u20ac1.2K in en-US

 // Create a formatter in a private static final field:
 private static final 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 private static final field but without setting a locale until the call site:
 private static final UnlocalizedNumberFormatter template = NumberFormatter.with()
     .sign(SignDisplay.ALWAYS)
     .unitWidth(UnitWidth.FULL_NAME);
 template.locale(...).format(new Measure(1234, MeasureUnit.METER)).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(ULocale.ENGLISH).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.

Note: To format monetary/currency values, specify the currency in the `.unit()` function.

Summary

Public methods
`static UnlocalizedNumberFormatter`	`with()` Call this method at the beginning of a NumberFormatter fluent chain in which the locale is not currently known at the call site.
`static LocalizedNumberFormatter`	`withLocale(Locale locale)` Call this method at the beginning of a NumberFormatter fluent chain in which the locale is known at the call site.
`static LocalizedNumberFormatter`	`withLocale(ULocale locale)` Call this method at the beginning of a NumberFormatter fluent chain in which the locale is known at the call site.

Inherited methods

From class


        
          java.lang.Object

`Object`	`clone()` Creates and returns a copy of this object.
`boolean`	`equals(Object obj)` Indicates whether some other object is "equal to" this one.
`void`	`finalize()` Called by the garbage collector on an object when garbage collection determines that there are no more references to the object.
`final Class<?>`	`getClass()` Returns the runtime class of this `Object`.
`int`	`hashCode()` Returns a hash code value for the object.
`final void`	`notify()` Wakes up a single thread that is waiting on this object's monitor.
`final void`	`notifyAll()` Wakes up all threads that are waiting on this object's monitor.
`String`	`toString()` Returns a string representation of the object.
`final void`	`wait(long timeoutMillis, int nanos)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait(long timeoutMillis)` Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
`final void`	`wait()` Causes the current thread to wait until it is awakened, typically by being notified or interrupted.

Public methods

with

Added in API level 30

public static UnlocalizedNumberFormatter with ()

Call this method at the beginning of a NumberFormatter fluent chain in which the locale is not currently known at the call site.

Returns
`UnlocalizedNumberFormatter`	An `UnlocalizedNumberFormatter`, to be used for chaining.

withLocale

Added in API level 30

public static LocalizedNumberFormatter withLocale (Locale locale)

Call this method at the beginning of a NumberFormatter fluent chain in which the locale is known at the call site.

Parameters
`locale`	`Locale`: The locale from which to load formats and symbols for number formatting.

Returns
`LocalizedNumberFormatter`	A `LocalizedNumberFormatter`, to be used for chaining.

withLocale

Added in API level 30

public static LocalizedNumberFormatter withLocale (ULocale locale)

Call this method at the beginning of a NumberFormatter fluent chain in which the locale is known at the call site.

Parameters
`locale`	`ULocale`: The locale from which to load formats and symbols for number formatting.

Returns
`LocalizedNumberFormatter`	A `LocalizedNumberFormatter`, to be used for chaining.