DecimalFormat

public class DecimalFormat
extends NumberFormat

java.lang.Object
   ↳ java.text.Format
     ↳ android.icu.text.UFormat
       ↳ android.icu.text.NumberFormat
         ↳ android.icu.text.DecimalFormat


[icu enhancement] ICU's replacement for DecimalFormat. Methods, fields, and other functionality specific to ICU are labeled '[icu]'.

IMPORTANT: New users are strongly encouraged to see if NumberFormatter fits their use case. Although not deprecated, this class, DecimalFormat, is only provided for java.text.DecimalFormat compatibility.


DecimalFormat is the primary concrete subclass of NumberFormat. It has a variety of features designed to make it possible to parse and format numbers in any locale, including support for Western, Arabic, or Indic digits. It supports different flavors of numbers, including integers ("123"), fixed-point numbers ("123.4"), scientific notation ("1.23E4"), percentages ("12%"), and currency amounts ("$123.00", "USD123.00", "123.00 US dollars"). All of these flavors can be easily localized.

To obtain a number formatter for a specific locale (including the default locale), call one of NumberFormat's factory methods such as NumberFormat#getInstance. Do not call DecimalFormat constructors directly unless you know what you are doing.

DecimalFormat aims to comply with the specification UTS #35. Read the specification for more information on how all the properties in DecimalFormat fit together.

NOTE: Starting in ICU 60, there is a new set of APIs for localized number formatting that are designed to be an improvement over DecimalFormat. New users are discouraged from using DecimalFormat. For more information, see the package android.icu.number.

Example Usage

Customize settings on a DecimalFormat instance from the NumberFormat factory:

 NumberFormat f = NumberFormat.getInstance(loc);
 if (f instanceof DecimalFormat) {
     ((DecimalFormat) f).setDecimalSeparatorAlwaysShown(true);
     ((DecimalFormat) f).setMinimumGroupingDigits(2);
 }
 

Quick and dirty print out a number using the localized number, currency, and percent format for each locale:

 for (ULocale uloc : ULocale.getAvailableLocales()) {
     System.out.print(uloc + ":\t");
     System.out.print(NumberFormat.getInstance(uloc).format(1.23));
     System.out.print("\t");
     System.out.print(NumberFormat.getCurrencyInstance(uloc).format(1.23));
     System.out.print("\t");
     System.out.print(NumberFormat.getPercentInstance(uloc).format(1.23));
     System.out.println();
 }
 

Properties and Symbols

A DecimalFormat object encapsulates a set of properties and a set of symbols. Grouping size, rounding mode, and affixes are examples of properties. Locale digits and the characters used for grouping and decimal separators are examples of symbols.

To set a custom set of symbols, use setDecimalFormatSymbols(DecimalFormatSymbols). Use the various other setters in this class to set custom values for the properties.

Rounding

DecimalFormat provides three main strategies to specify the position at which numbers should be rounded:

  1. Magnitude: Display a fixed number of fraction digits; this is the most common form.
  2. Increment: Round numbers to the closest multiple of a certain increment, such as 0.05. This is common in currencies.
  3. Significant Digits: Round numbers such that a fixed number of nonzero digits are shown. This is most common in scientific notation.

It is not possible to specify more than one rounding strategy. For example, setting a rounding increment in conjunction with significant digits results in undefined behavior.

It is also possible to specify the rounding mode to use. The default rounding mode is "half even", which rounds numbers to their closest increment, with ties broken in favor of trailing numbers being even. For more information, see setRoundingMode(int) and the ICU User Guide.

Pattern Strings

A pattern string is a way to serialize some of the available properties for decimal formatting. However, not all properties are capable of being serialized into a pattern string; see applyPattern(String) for more information.

Most users should not need to interface with pattern strings directly.

ICU DecimalFormat aims to follow the specification for pattern strings in UTS #35. Refer to that specification for more information on pattern string syntax.

Pattern String BNF

The following BNF is used when parsing the pattern string into property values:
 pattern    := subpattern (';' subpattern)?
 subpattern := prefix? number exponent? suffix?
 number     := (integer ('.' fraction)?) | sigDigits
 prefix     := '\u0000'..'\uFFFD' - specialCharacters
 suffix     := '\u0000'..'\uFFFD' - specialCharacters
 integer    := '#'* '0'* '0'
 fraction   := '0'* '#'*
 sigDigits  := '#'* '@' '@'* '#'*
 exponent   := 'E' '+'? '0'* '0'
 padSpec    := '*' padChar
 padChar    := '\u0000'..'\uFFFD' - quote
  
 Notation:
   X*       0 or more instances of X
   X?       0 or 1 instances of X
   X|Y      either X or Y
   C..D     any character from C up to D, inclusive
   S-T      characters in S, except those in T
 

The first subpattern is for positive numbers. The second (optional) subpattern is for negative numbers.

Not indicated in the BNF syntax above:

  • The grouping separator ',' can occur inside the integer and sigDigits elements, between any two pattern characters of that element, as long as the integer or sigDigits element is not followed by the exponent element.
  • Two grouping intervals are recognized: That between the decimal point and the first grouping symbol, and that between the first and second grouping symbols. These intervals are identical in most locales, but in some locales they differ. For example, the pattern "#,##,###" formats the number 123456789 as "12,34,56,789".
  • The pad specifier padSpec may appear before the prefix, after the prefix, before the suffix, after the suffix, or not at all.
  • In place of '0', the digits '1' through '9' may be used to indicate a rounding increment.

Parsing

DecimalFormat aims to be able to parse anything that it can output as a formatted string.

There are two primary parse modes: lenient and strict. Lenient mode should be used if the goal is to parse user input to a number; strict mode should be used if the goal is validation. The default is lenient mode. For more information, see setParseStrict(boolean).

DecimalFormat parses all Unicode characters that represent decimal digits, as defined by UCharacter#digit. In addition, DecimalFormat also recognizes as digits the ten consecutive characters starting with the localized zero digit defined in the DecimalFormatSymbols object. During formatting, the DecimalFormatSymbols-based digits are output.

Grouping separators are ignored in lenient mode (default). In strict mode, grouping separators must match the locale-specified grouping sizes.

When using parseCurrency(CharSequence, ParsePosition), all currencies are accepted, not just the currency currently set in the formatter. In addition, the formatter is able to parse every currency style format for a particular locale no matter which style the formatter is constructed with. For example, a formatter instance gotten from NumberFormat.getInstance(ULocale, NumberFormat.CURRENCYSTYLE) can parse both "USD1.00" and "3.00 US dollars".

Whitespace characters (lenient mode) and control characters (lenient and strict mode), collectively called "ignorables", do not need to match in identity or quantity between the pattern string and the input string. For example, the pattern "# %" matches "35 %" (with a single space), "35%" (with no space), "35 %" (with a non-breaking space), and "35  %" (with multiple spaces). Arbitrary ignorables are also allowed at boundaries between the parts of the number: prefix, number, exponent separator, and suffix. Ignorable whitespace characters are those having the Unicode "blank" property for regular expressions, defined in UTS #18 Annex C, which is "horizontal" whitespace, like spaces and tabs, but not "vertical" whitespace, like line breaks. Ignorable control characters are those in the Unicode set [:Default_Ignorable_Code_Point:].

If parse(java.lang.String, java.text.ParsePosition) fails to parse a string, it returns null and leaves the parse position unchanged. The convenience method NumberFormat.parse(java.lang.String) indicates parse failure by throwing a ParseException.

Under the hood, a state table parsing engine is used. To debug a parsing failure during development, use the following pattern to print details about the state table transitions:

 android.icu.impl.number.Parse.DEBUGGING = true;
 df.parse("123.45", ppos);
 android.icu.impl.number.Parse.DEBUGGING = false;
 

Thread Safety and Best Practices

Starting with ICU 59, instances of DecimalFormat are thread-safe.

Under the hood, DecimalFormat maintains an immutable formatter object that is rebuilt whenever any of the property setters are called. It is therefore best practice to call property setters only during construction and not when formatting numbers online.

See also:

Summary

Constants

int MINIMUM_GROUPING_DIGITS_AUTO

[icu] Constant for setMinimumGroupingDigits(int) to specify display grouping using the default strategy for all locales.

int MINIMUM_GROUPING_DIGITS_MIN2

[icu] Constant for setMinimumGroupingDigits(int) to specify display grouping using locale defaults, except do not show grouping on values smaller than 10000 (such that there is a minimum of two digits before the first separator).

int PAD_AFTER_PREFIX

[icu] Constant for getPadPosition() and setPadPosition(int) to specify pad characters inserted after the prefix.

int PAD_AFTER_SUFFIX

[icu] Constant for getPadPosition() and setPadPosition(int) to specify pad characters inserted after the suffix.

int PAD_BEFORE_PREFIX

[icu] Constant for getPadPosition() and setPadPosition(int) to specify pad characters inserted before the prefix.

int PAD_BEFORE_SUFFIX

[icu] Constant for getPadPosition() and setPadPosition(int) to specify pad characters inserted before the suffix.

Inherited constants

Public constructors

DecimalFormat()

Creates a DecimalFormat based on the number pattern and symbols for the default locale.

DecimalFormat(String pattern)

Creates a DecimalFormat based on the given pattern, using symbols for the default locale.

DecimalFormat(String pattern, DecimalFormatSymbols symbols)

Creates a DecimalFormat based on the given pattern and symbols.

DecimalFormat(String pattern, DecimalFormatSymbols symbols, CurrencyPluralInfo infoInput, int style)

Creates a DecimalFormat based on the given pattern and symbols, with additional control over the behavior of currency.

Public methods

void applyLocalizedPattern(String localizedPattern)

Converts the given string to standard notation and then parses it using applyPattern(String).

void applyPattern(String pattern)

Parses the given pattern string and overwrites the settings specified in the pattern string.

boolean areSignificantDigitsUsed()

[icu] Returns whether significant digits are being used in rounding.

Object clone()

Overrides clone.

boolean equals(Object obj)

Tests for equality between this formatter and another formatter.

StringBuffer format(BigInteger number, StringBuffer result, FieldPosition fieldPosition)

[icu] Formats a BigInteger.

StringBuffer format(CurrencyAmount currAmt, StringBuffer result, FieldPosition fieldPosition)

[icu] Formats a CurrencyAmount.

StringBuffer format(BigDecimal number, StringBuffer result, FieldPosition fieldPosition)

[icu] Formats an ICU BigDecimal.

StringBuffer format(double number, StringBuffer result, FieldPosition fieldPosition)

Specialization of format.

StringBuffer format(BigDecimal number, StringBuffer result, FieldPosition fieldPosition)

[icu] Formats a BigDecimal.

StringBuffer format(long number, StringBuffer result, FieldPosition fieldPosition)

Specialization of format.

AttributedCharacterIterator formatToCharacterIterator(Object obj)

Formats an Object producing an AttributedCharacterIterator.

Currency getCurrency()

Returns the currency used to display currency amounts.

CurrencyPluralInfo getCurrencyPluralInfo()

[icu] Returns the current instance of CurrencyPluralInfo.

Currency.CurrencyUsage getCurrencyUsage()

[icu] Returns the strategy for rounding currency amounts.

DecimalFormatSymbols getDecimalFormatSymbols()

Returns a copy of the decimal format symbols used by this formatter.

int getFormatWidth()

Returns the minimum number of characters in formatted output.

int getGroupingSize()

Returns the primary grouping size in use.

MathContext getMathContext()

[icu] Returns the MathContext being used to round numbers.

MathContext getMathContextICU()

[icu] Returns the MathContext being used to round numbers.

int getMaximumFractionDigits()

Returns the effective maximum number of integer digits after the decimal separator.

int getMaximumIntegerDigits()

Returns the effective maximum number of digits before the decimal separator.

int getMaximumSignificantDigits()

[icu] Returns the effective maximum number of significant digits displayed.

byte getMinimumExponentDigits()

[icu] Returns the minimum number of digits printed in the exponent in scientific notation.

int getMinimumFractionDigits()

Returns the effective minimum number of integer digits after the decimal separator.

int getMinimumGroupingDigits()

[icu] Returns the minimum number of digits before grouping is triggered.

int getMinimumIntegerDigits()

Returns the effective minimum number of digits before the decimal separator.

int getMinimumSignificantDigits()

[icu] Returns the effective minimum number of significant digits displayed.

int getMultiplier()

Returns the multiplier being applied to numbers before they are formatted.

String getNegativePrefix()

Affixes: Gets the negative prefix string currently being used to format numbers.

String getNegativeSuffix()

Affixes: Gets the negative suffix string currently being used to format numbers.

char getPadCharacter()

[icu] Returns the character used for padding.

int getPadPosition()

[icu] Returns the position used for padding.

int getParseMaxDigits()

This method was deprecated in API level 28. Setting max parse digits has no effect since ICU4J 59.

String getPositivePrefix()

Affixes: Gets the positive prefix string currently being used to format numbers.

String getPositiveSuffix()

Affixes: Gets the positive suffix string currently being used to format numbers.

BigDecimal getRoundingIncrement()

[icu] Returns the increment to which numbers are being rounded.

int getRoundingMode()

Returns the rounding mode being used to round numbers.

int getSecondaryGroupingSize()

[icu] Returns the secondary grouping size in use.

int hashCode()

Returns a hash code value for the object.

boolean isDecimalPatternMatchRequired()

[icu] Returns whether the presence of a decimal point must match the pattern.

boolean isDecimalSeparatorAlwaysShown()

Returns whether the decimal separator is shown on integers.

boolean isExponentSignAlwaysShown()

[icu] Returns whether the sign (plus or minus) is always printed in scientific notation.

boolean isGroupingUsed()

Returns whether or not grouping separators are being printed in the output.

boolean isParseBigDecimal()

Returns whether NumberFormat.parse(String) will always return a BigDecimal.

boolean isParseCaseSensitive()

[icu] Returns whether to force case (uppercase/lowercase) to match when parsing.

boolean isParseIntegerOnly()

Returns true if this format will parse numbers as integers only.

boolean isParseNoExponent()

[icu] Returns whether to ignore exponents when parsing.

boolean isParseStrict()

[icu] Returns whether strict parsing is in effect.

boolean isScientificNotation()

[icu] Returns whether scientific (exponential) notation is enabled on this formatter.

boolean isSignAlwaysShown()

[icu] Returns whether the sign is being shown on positive numbers.

Number parse(String text, ParsePosition parsePosition)

Returns a Long if possible (e.g., within the range [Long.MIN_VALUE, Long.MAX_VALUE] and with no decimals); otherwise, returns another type, such as a BigDecimal, BigInteger, or Double.

CurrencyAmount parseCurrency(CharSequence text, ParsePosition parsePosition)

Parses text from the given string as a CurrencyAmount.

void setCurrency(Currency currency)

Sets the currency to be used when formatting numbers.

void setCurrencyPluralInfo(CurrencyPluralInfo newInfo)

[icu] Sets a custom instance of CurrencyPluralInfo.

void setCurrencyUsage(Currency.CurrencyUsage usage)

[icu] Sets the currency-dependent strategy to use when rounding numbers.

void setDecimalFormatSymbols(DecimalFormatSymbols newSymbols)

Sets the decimal format symbols used by this formatter.

void setDecimalPatternMatchRequired(boolean value)

[icu] Parsing: This method is used to either require or forbid the presence of a decimal point in the string being parsed (disabled by default).

void setDecimalSeparatorAlwaysShown(boolean value)

Separators: Sets whether the decimal separator (a period in en-US) is shown on integers.

void setExponentSignAlwaysShown(boolean expSignAlways)

[icu] Scientific Notation: Sets whether the sign (plus or minus) is always to be shown in the exponent in scientific notation.

void setFormatWidth(int width)

Padding: Sets the minimum width of the string output by the formatting pipeline.

void setGroupingSize(int width)

Grouping: Sets the primary grouping size (distance between grouping separators) used when formatting large numbers.

void setGroupingUsed(boolean enabled)

Grouping: Sets whether grouping is to be used when formatting numbers.

void setMathContext(MathContext mathContext)

[icu] Rounding and Digit Limits: Sets the MathContext used to round numbers.

void setMathContextICU(MathContext mathContextICU)

[icu] Rounding and Digit Limits: Overload of setMathContext(MathContext) for MathContext.

void setMaximumFractionDigits(int value)

Rounding and Digit Limits: Sets the maximum number of digits to display after the decimal separator.

void setMaximumIntegerDigits(int value)

Rounding and Digit Limits: Sets the maximum number of digits to display before the decimal separator.

void setMaximumSignificantDigits(int value)

[icu] Rounding and Digit Limits: Sets the maximum number of significant digits to be displayed.

void setMinimumExponentDigits(byte minExpDig)

[icu] Scientific Notation: Sets the minimum number of digits to be printed in the exponent.

void setMinimumFractionDigits(int value)

Rounding and Digit Limits: Sets the minimum number of digits to display after the decimal separator.

void setMinimumGroupingDigits(int number)

[icu] Sets the minimum number of digits that must be before the first grouping separator in order for the grouping separator to be printed.

void setMinimumIntegerDigits(int value)

Rounding and Digit Limits: Sets the minimum number of digits to display before the decimal separator.

void setMinimumSignificantDigits(int value)

[icu] Rounding and Digit Limits: Sets the minimum number of significant digits to be displayed.

void setMultiplier(int multiplier)

Sets a number that will be used to multiply all numbers prior to formatting.

void setNegativePrefix(String prefix)

Affixes: Sets the string to prepend to negative numbers.

void setNegativeSuffix(String suffix)

Affixes: Sets the string to append to negative numbers.

void setPadCharacter(char padChar)

[icu] Padding: Sets the character used to pad numbers that are narrower than the width specified in setFormatWidth(int).

void setPadPosition(int padPos)

[icu] Padding: Sets the position where to insert the pad character when narrower than the width specified in setFormatWidth(int).

void setParseBigDecimal(boolean value)

Whether to make NumberFormat.parse(String) prefer returning a BigDecimal when possible.

void setParseCaseSensitive(boolean value)

[icu] Specifies whether parsing should require cases to match in affixes, exponent separators, and currency codes.

void setParseIntegerOnly(boolean parseIntegerOnly)

Parsing: Sets whether to ignore the fraction part of a number when parsing (defaults to false).

This is functionally equivalent to calling setDecimalPatternMatchRequired(boolean) and a pattern without a decimal point.

void setParseMaxDigits(int maxDigits)

This method was deprecated in API level 28. Setting max parse digits has no effect since ICU4J 59.

void setParseNoExponent(boolean value)

[icu] Specifies whether to stop parsing when an exponent separator is encountered.

void setParseStrict(boolean parseStrict)

[icu] Sets whether strict parsing is in effect.

void setPositivePrefix(String prefix)

Affixes: Sets the string to prepend to positive numbers.

void setPositiveSuffix(String suffix)

Affixes: Sets the string to append to positive numbers.

void setRoundingIncrement(BigDecimal increment)

[icu] Rounding and Digit Limits: Sets an increment, or interval, to which numbers are rounded.

void setRoundingIncrement(BigDecimal increment)

[icu] Rounding and Digit Limits: Overload of setRoundingIncrement(java.math.BigDecimal).

void setRoundingIncrement(double increment)

[icu] Rounding and Digit Limits: Overload of setRoundingIncrement(java.math.BigDecimal).

void setRoundingMode(int roundingMode)

Rounding and Digit Limits: Sets the RoundingMode used to round numbers.

void setScientificNotation(boolean useScientific)

[icu] Scientific Notation: Sets whether this formatter should print in scientific (exponential) notation.

void setSecondaryGroupingSize(int width)

[icu] Grouping: Sets the secondary grouping size (distance between grouping separators after the first separator) used when formatting large numbers.

void setSignAlwaysShown(boolean value)

Sets whether to always shown the plus sign ('+' in en) on positive numbers.

void setSignificantDigitsUsed(boolean useSignificantDigits)

[icu] Rounding and Digit Limits: Sets whether significant digits are to be used in rounding.

String toLocalizedPattern()

Calls toPattern() and converts the string to localized notation.

String toPattern()

Serializes this formatter object to a decimal format pattern string.

String toString()

Returns the default value of toString() with extra DecimalFormat-specific information appended to the end of the string.

Inherited methods

Constants

MINIMUM_GROUPING_DIGITS_AUTO

Added in API level 33
public static final int MINIMUM_GROUPING_DIGITS_AUTO

[icu] Constant for setMinimumGroupingDigits(int) to specify display grouping using the default strategy for all locales.

Constant Value: -2 (0xfffffffe)

MINIMUM_GROUPING_DIGITS_MIN2

Added in API level 33
public static final int MINIMUM_GROUPING_DIGITS_MIN2

[icu] Constant for setMinimumGroupingDigits(int) to specify display grouping using locale defaults, except do not show grouping on values smaller than 10000 (such that there is a minimum of two digits before the first separator).

Constant Value: -3 (0xfffffffd)

PAD_AFTER_PREFIX

Added in API level 24
public static final int PAD_AFTER_PREFIX

[icu] Constant for getPadPosition() and setPadPosition(int) to specify pad characters inserted after the prefix.

Constant Value: 1 (0x00000001)

PAD_AFTER_SUFFIX

Added in API level 24
public static final int PAD_AFTER_SUFFIX

[icu] Constant for getPadPosition() and setPadPosition(int) to specify pad characters inserted after the suffix.

Constant Value: 3 (0x00000003)

PAD_BEFORE_PREFIX

Added in API level 24
public static final int PAD_BEFORE_PREFIX

[icu] Constant for getPadPosition() and setPadPosition(int) to specify pad characters inserted before the prefix.

Constant Value: 0 (0x00000000)

PAD_BEFORE_SUFFIX

Added in API level 24
public static final int PAD_BEFORE_SUFFIX

[icu] Constant for getPadPosition() and setPadPosition(int) to specify pad characters inserted before the suffix.

Constant Value: 2 (0x00000002)

Public constructors

DecimalFormat

Added in API level 24
public DecimalFormat ()

Creates a DecimalFormat based on the number pattern and symbols for the default locale. This is a convenient way to obtain a DecimalFormat instance when internationalization is not the main concern.

Most users should call the factory methods on NumberFormat, such as NumberFormat.getNumberInstance(), which return localized formatter objects, instead of the DecimalFormat constructors.

DecimalFormat

Added in API level 24
public DecimalFormat (String pattern)

Creates a DecimalFormat based on the given pattern, using symbols for the default locale. This is a convenient way to obtain a DecimalFormat instance when internationalization is not the main concern.

Most users should call the factory methods on NumberFormat, such as NumberFormat.getNumberInstance(), which return localized formatter objects, instead of the DecimalFormat constructors.

Parameters
pattern String: A pattern string such as "#,##0.00" conforming to UTS #35.

Throws
IllegalArgumentException if the given pattern is invalid.

DecimalFormat

Added in API level 24
public DecimalFormat (String pattern, 
                DecimalFormatSymbols symbols)

Creates a DecimalFormat based on the given pattern and symbols. Use this constructor if you want complete control over the behavior of the formatter.

Most users should call the factory methods on NumberFormat, such as NumberFormat.getNumberInstance(), which return localized formatter objects, instead of the DecimalFormat constructors.

Parameters
pattern String: A pattern string such as "#,##0.00" conforming to UTS #35.

symbols DecimalFormatSymbols: The set of symbols to be used.

Throws
IllegalArgumentException if the given pattern is invalid

DecimalFormat

Added in API level 24
public DecimalFormat (String pattern, 
                DecimalFormatSymbols symbols, 
                CurrencyPluralInfo infoInput, 
                int style)

Creates a DecimalFormat based on the given pattern and symbols, with additional control over the behavior of currency. The style argument determines whether currency rounding rules should override the pattern, and the CurrencyPluralInfo object is used for customizing the plural forms used for currency long names.

Most users should call the factory methods on NumberFormat, such as NumberFormat.getNumberInstance(), which return localized formatter objects, instead of the DecimalFormat constructors.

Parameters
pattern String: a non-localized pattern string

symbols DecimalFormatSymbols: the set of symbols to be used

infoInput CurrencyPluralInfo: the information used for currency plural format, including currency plural patterns and plural rules.

style int: the decimal formatting style, it is one of the following values: NumberFormat.NUMBERSTYLE; NumberFormat.CURRENCYSTYLE; NumberFormat.PERCENTSTYLE; NumberFormat.SCIENTIFICSTYLE; NumberFormat.INTEGERSTYLE; NumberFormat.ISOCURRENCYSTYLE; NumberFormat.PLURALCURRENCYSTYLE;

Public methods

applyLocalizedPattern

Added in API level 24
public void applyLocalizedPattern (String localizedPattern)

Converts the given string to standard notation and then parses it using applyPattern(String). This method is provided for backwards compatibility and should not be used in new projects.

Localized notation means that instead of using generic placeholders in the pattern, you use the corresponding locale-specific characters instead. For example, in locale fr-FR, the period in the pattern "0.000" means "decimal" in standard notation (as it does in every other locale), but it means "grouping" in localized notation.

Parameters
localizedPattern String: The pattern string in localized notation.

applyPattern

Added in API level 24
public void applyPattern (String pattern)

Parses the given pattern string and overwrites the settings specified in the pattern string. The properties corresponding to the following setters are overwritten, either with their default values or with the value specified in the pattern string:

  1. setDecimalSeparatorAlwaysShown(boolean)
  2. setExponentSignAlwaysShown(boolean)
  3. setFormatWidth(int)
  4. setGroupingSize(int)
  5. setMultiplier(int) (percent/permille)
  6. setMaximumFractionDigits(int)
  7. setMaximumIntegerDigits(int)
  8. setMaximumSignificantDigits(int)
  9. setMinimumExponentDigits(byte)
  10. setMinimumFractionDigits(int)
  11. setMinimumIntegerDigits(int)
  12. setMinimumSignificantDigits(int)
  13. setPadPosition(int)
  14. setPadCharacter(char)
  15. setRoundingIncrement(BigDecimal)
  16. setSecondaryGroupingSize(int)
All other settings remain untouched.

For more information on pattern strings, see UTS #35.

Parameters
pattern String

areSignificantDigitsUsed

Added in API level 24
public boolean areSignificantDigitsUsed ()

[icu] Returns whether significant digits are being used in rounding.

Returns
boolean

clone

Added in API level 24
public Object clone ()

Overrides clone.

Returns
Object a clone of this instance.

equals

Added in API level 24
public boolean equals (Object obj)

Tests for equality between this formatter and another formatter.

If two DecimalFormat instances are equal, then they will always produce the same output. However, the reverse is not necessarily true: if two DecimalFormat instances always produce the same output, they are not necessarily equal.

Parameters
obj Object: the object to compare against

Returns
boolean true if the object is equal to this.

format

Added in API level 24
public StringBuffer format (BigInteger number, 
                StringBuffer result, 
                FieldPosition fieldPosition)

[icu] Formats a BigInteger. Specialization of format.

Parameters
number BigInteger

result StringBuffer

fieldPosition FieldPosition

Returns
StringBuffer

format

Added in API level 24
public StringBuffer format (CurrencyAmount currAmt, 
                StringBuffer result, 
                FieldPosition fieldPosition)

[icu] Formats a CurrencyAmount. Specialization of format.

Parameters
currAmt CurrencyAmount

result StringBuffer

fieldPosition FieldPosition

Returns
StringBuffer

format

Added in API level 24
public StringBuffer format (BigDecimal number, 
                StringBuffer result, 
                FieldPosition fieldPosition)

[icu] Formats an ICU BigDecimal. Specialization of format.

Parameters
number BigDecimal

result StringBuffer

fieldPosition FieldPosition

Returns
StringBuffer

format

Added in API level 24
public StringBuffer format (double number, 
                StringBuffer result, 
                FieldPosition fieldPosition)

Specialization of format.

Parameters
number double

result StringBuffer

fieldPosition FieldPosition

Returns
StringBuffer

format

Added in API level 24
public StringBuffer format (BigDecimal number, 
                StringBuffer result, 
                FieldPosition fieldPosition)

[icu] Formats a BigDecimal. Specialization of format.

Parameters
number BigDecimal

result StringBuffer

fieldPosition FieldPosition

Returns
StringBuffer

format

Added in API level 24
public StringBuffer format (long number, 
                StringBuffer result, 
                FieldPosition fieldPosition)

Specialization of format.

Parameters
number long

result StringBuffer

fieldPosition FieldPosition

Returns
StringBuffer

formatToCharacterIterator

Added in API level 24
public AttributedCharacterIterator formatToCharacterIterator (Object obj)

Formats an Object producing an AttributedCharacterIterator. You can use the returned AttributedCharacterIterator to build the resulting String, as well as to determine information about the resulting String.

Each attribute key of the AttributedCharacterIterator will be of type Field. It is up to each Format implementation to define what the legal values are for each attribute in the AttributedCharacterIterator, but typically the attribute key is also used as the attribute value.

The default implementation creates an AttributedCharacterIterator with no attributes. Subclasses that support fields should override this and create an AttributedCharacterIterator with meaningful attributes.

Parameters
obj Object: The object to format

Returns
AttributedCharacterIterator AttributedCharacterIterator describing the formatted value.

getCurrency

Added in API level 24
public Currency getCurrency ()

Returns the currency used to display currency amounts. May be null.

Returns
Currency

getCurrencyPluralInfo

Added in API level 24
public CurrencyPluralInfo getCurrencyPluralInfo ()

[icu] Returns the current instance of CurrencyPluralInfo.

Returns
CurrencyPluralInfo

getCurrencyUsage

Added in API level 24
public Currency.CurrencyUsage getCurrencyUsage ()

[icu] Returns the strategy for rounding currency amounts.

Returns
Currency.CurrencyUsage

getDecimalFormatSymbols

Added in API level 24
public DecimalFormatSymbols getDecimalFormatSymbols ()

Returns a copy of the decimal format symbols used by this formatter.

Returns
DecimalFormatSymbols desired DecimalFormatSymbols

getFormatWidth

Added in API level 24
public int getFormatWidth ()

Returns the minimum number of characters in formatted output.

Returns
int

getGroupingSize

Added in API level 24
public int getGroupingSize ()

Returns the primary grouping size in use.

Returns
int

getMathContext

Added in API level 24
public MathContext getMathContext ()

[icu] Returns the MathContext being used to round numbers.

Returns
MathContext

getMathContextICU

Added in API level 24
public MathContext getMathContextICU ()

[icu] Returns the MathContext being used to round numbers.

Returns
MathContext

getMaximumFractionDigits

Added in API level 24
public int getMaximumFractionDigits ()

Returns the effective maximum number of integer digits after the decimal separator.

Returns
int the maximum number of fraction digits

getMaximumIntegerDigits

Added in API level 24
public int getMaximumIntegerDigits ()

Returns the effective maximum number of digits before the decimal separator.

Returns
int the maximum number of integer digits

getMaximumSignificantDigits

Added in API level 24
public int getMaximumSignificantDigits ()

[icu] Returns the effective maximum number of significant digits displayed.

Returns
int

getMinimumExponentDigits

Added in API level 24
public byte getMinimumExponentDigits ()

[icu] Returns the minimum number of digits printed in the exponent in scientific notation.

Returns
byte

getMinimumFractionDigits

Added in API level 24
public int getMinimumFractionDigits ()

Returns the effective minimum number of integer digits after the decimal separator.

Returns
int the minimum number of fraction digits

getMinimumGroupingDigits

Added in API level 31
public int getMinimumGroupingDigits ()

[icu] Returns the minimum number of digits before grouping is triggered.

Returns
int

getMinimumIntegerDigits

Added in API level 24
public int getMinimumIntegerDigits ()

Returns the effective minimum number of digits before the decimal separator.

Returns
int the minimum number of integer digits

getMinimumSignificantDigits

Added in API level 24
public int getMinimumSignificantDigits ()

[icu] Returns the effective minimum number of significant digits displayed.

Returns
int

getMultiplier

Added in API level 24
public int getMultiplier ()

Returns the multiplier being applied to numbers before they are formatted.

Returns
int

See also:

getNegativePrefix

Added in API level 24
public String getNegativePrefix ()

Affixes: Gets the negative prefix string currently being used to format numbers.

If the affix was specified via the pattern, the string returned by this method will have locale symbols substituted in place of special characters according to the LDML specification. If the affix was specified via setNegativePrefix(String), the string will be returned literally.

Returns
String The string being prepended to negative numbers.

getNegativeSuffix

Added in API level 24
public String getNegativeSuffix ()

Affixes: Gets the negative suffix string currently being used to format numbers.

If the affix was specified via the pattern, the string returned by this method will have locale symbols substituted in place of special characters according to the LDML specification. If the affix was specified via setNegativeSuffix(String), the string will be returned literally.

Returns
String The string being appended to negative numbers.

getPadCharacter

Added in API level 24
public char getPadCharacter ()

[icu] Returns the character used for padding.

Returns
char

getPadPosition

Added in API level 24
public int getPadPosition ()

[icu] Returns the position used for padding.

Returns
int

getParseMaxDigits

Added in API level 24
Deprecated in API level 28
public int getParseMaxDigits ()

This method was deprecated in API level 28.
Setting max parse digits has no effect since ICU4J 59.

Always returns 1000, the default prior to ICU 59.

Returns
int

getPositivePrefix

Added in API level 24
public String getPositivePrefix ()

Affixes: Gets the positive prefix string currently being used to format numbers.

If the affix was specified via the pattern, the string returned by this method will have locale symbols substituted in place of special characters according to the LDML specification. If the affix was specified via setPositivePrefix(String), the string will be returned literally.

Returns
String The string being prepended to positive numbers.

getPositiveSuffix

Added in API level 24
public String getPositiveSuffix ()

Affixes: Gets the positive suffix string currently being used to format numbers.

If the affix was specified via the pattern, the string returned by this method will have locale symbols substituted in place of special characters according to the LDML specification. If the affix was specified via setPositiveSuffix(String), the string will be returned literally.

Returns
String The string being appended to positive numbers.

getRoundingIncrement

Added in API level 24
public BigDecimal getRoundingIncrement ()

[icu] Returns the increment to which numbers are being rounded.

Returns
BigDecimal

getRoundingMode

Added in API level 24
public int getRoundingMode ()

Returns the rounding mode being used to round numbers.

Returns
int A rounding mode, between BigDecimal.ROUND_UP and BigDecimal.ROUND_UNNECESSARY.

getSecondaryGroupingSize

Added in API level 24
public int getSecondaryGroupingSize ()

[icu] Returns the secondary grouping size in use.

Returns
int

hashCode

Added in API level 24
public int hashCode ()

Returns a hash code value for the object. This method is supported for the benefit of hash tables such as those provided by HashMap.

The general contract of hashCode is:

  • Whenever it is invoked on the same object more than once during an execution of a Java application, the hashCode method must consistently return the same integer, provided no information used in equals comparisons on the object is modified. This integer need not remain consistent from one execution of an application to another execution of the same application.
  • If two objects are equal according to the equals method, then calling the hashCode method on each of the two objects must produce the same integer result.
  • It is not required that if two objects are unequal according to the equals method, then calling the hashCode method on each of the two objects must produce distinct integer results. However, the programmer should be aware that producing distinct integer results for unequal objects may improve the performance of hash tables.

Returns
int a hash code value for this object.

isDecimalPatternMatchRequired

Added in API level 24
public boolean isDecimalPatternMatchRequired ()

[icu] Returns whether the presence of a decimal point must match the pattern.

Returns
boolean

isDecimalSeparatorAlwaysShown

Added in API level 24
public boolean isDecimalSeparatorAlwaysShown ()

Returns whether the decimal separator is shown on integers.

Returns
boolean

isExponentSignAlwaysShown

Added in API level 24
public boolean isExponentSignAlwaysShown ()

[icu] Returns whether the sign (plus or minus) is always printed in scientific notation.

Returns
boolean

isGroupingUsed

Added in API level 24
public boolean isGroupingUsed ()

Returns whether or not grouping separators are being printed in the output.

Returns
boolean true if grouping is used

isParseBigDecimal

Added in API level 24
public boolean isParseBigDecimal ()

Returns whether NumberFormat.parse(String) will always return a BigDecimal.

Returns
boolean

isParseCaseSensitive

Added in API level 31
public boolean isParseCaseSensitive ()

[icu] Returns whether to force case (uppercase/lowercase) to match when parsing.

Returns
boolean

isParseIntegerOnly

Added in API level 24
public boolean isParseIntegerOnly ()

Returns true if this format will parse numbers as integers only. For example in the English locale, with ParseIntegerOnly true, the string "1234." would be parsed as the integer value 1234 and parsing would stop at the "." character. The decimal separator accepted by the parse operation is locale-dependent and determined by the subclass.

Returns
boolean true if this will parse integers only

isParseNoExponent

Added in API level 31
public boolean isParseNoExponent ()

[icu] Returns whether to ignore exponents when parsing.

Returns
boolean

isParseStrict

Added in API level 24
public boolean isParseStrict ()

[icu] Returns whether strict parsing is in effect.

Returns
boolean true if strict parsing is in effect

isScientificNotation

Added in API level 24
public boolean isScientificNotation ()

[icu] Returns whether scientific (exponential) notation is enabled on this formatter.

Returns
boolean

isSignAlwaysShown

Added in API level 31
public boolean isSignAlwaysShown ()

[icu] Returns whether the sign is being shown on positive numbers.

Returns
boolean Whether the sign is shown on positive numbers and zero.

parse

Added in API level 24
public Number parse (String text, 
                ParsePosition parsePosition)

Returns a Long if possible (e.g., within the range [Long.MIN_VALUE, Long.MAX_VALUE] and with no decimals); otherwise, returns another type, such as a BigDecimal, BigInteger, or Double. The return type is not guaranteed other than for the Long case.

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).

Does not throw an exception; if no object can be parsed, index is unchanged!

For more detail on parsing, see the "Parsing" header in the class documentation of DecimalFormat.

Parameters
text String

parsePosition ParsePosition

Returns
Number

parseCurrency

Added in API level 24
public CurrencyAmount parseCurrency (CharSequence text, 
                ParsePosition parsePosition)

Parses text from the given string as a CurrencyAmount. Unlike the parse() method, this method will attempt to parse a generic currency name, searching for a match of this object's locale's currency display names, or for a 3-letter ISO currency code. This method will fail if this format is not a currency format, that is, if it does not contain the currency pattern symbol (U+00A4) in its prefix or suffix.

Parameters
text CharSequence: the text to parse

parsePosition ParsePosition: input-output position; on input, the position within text to match; must have 0 <= pos.getIndex() < text.length(); on output, the position after the last matched character. If the parse fails, the position in unchanged upon output.

Returns
CurrencyAmount a CurrencyAmount, or null upon failure

setCurrency

Added in API level 24
public void setCurrency (Currency currency)

Sets the currency to be used when formatting numbers. The effect is twofold:

  1. Substitutions for currency symbols in the pattern string will use this currency
  2. The rounding mode will obey the rules for this currency (see setCurrencyUsage(CurrencyUsage))
Important: Displaying the currency in the output requires that the patter associated with this formatter contains a currency symbol '¤'. This will be the case if the instance was created via NumberFormat.getCurrencyInstance() or one of its friends.

Parameters
currency Currency: The currency to use.

setCurrencyPluralInfo

Added in API level 24
public void setCurrencyPluralInfo (CurrencyPluralInfo newInfo)

[icu] Sets a custom instance of CurrencyPluralInfo. CurrencyPluralInfo generates pattern strings for printing currency long names.

Most users should not call this method directly. You should instead create your formatter via NumberFormat.getInstance(NumberFormat.PLURALCURRENCYSTYLE).

Parameters
newInfo CurrencyPluralInfo: The CurrencyPluralInfo to use when printing currency long names.

setCurrencyUsage

Added in API level 24
public void setCurrencyUsage (Currency.CurrencyUsage usage)

[icu] Sets the currency-dependent strategy to use when rounding numbers. There are two strategies:

  • STANDARD: When the amount displayed is intended for banking statements or electronic transfer.
  • CASH: When the amount displayed is intended to be representable in physical currency, like at a cash register.
CASH mode is relevant in currencies that do not have tender down to the penny. For more information on the two rounding strategies, see UTS #35. If omitted, the strategy defaults to STANDARD. To override currency rounding altogether, use setMinimumFractionDigits(int) and setMaximumFractionDigits(int) or setRoundingIncrement(BigDecimal).

Parameters
usage Currency.CurrencyUsage: The strategy to use when rounding in the current currency.

setDecimalFormatSymbols

Added in API level 24
public void setDecimalFormatSymbols (DecimalFormatSymbols newSymbols)

Sets the decimal format symbols used by this formatter. The formatter uses a copy of the provided symbols.

Parameters
newSymbols DecimalFormatSymbols: desired DecimalFormatSymbols

setDecimalPatternMatchRequired

Added in API level 24
public void setDecimalPatternMatchRequired (boolean value)

[icu] Parsing: This method is used to either require or forbid the presence of a decimal point in the string being parsed (disabled by default). This feature was designed to be an extra layer of strictness on top of strict parsing, although it can be used in either lenient mode or strict mode.

To require a decimal point, call this method in combination with either a pattern containing a decimal point or with setDecimalSeparatorAlwaysShown(boolean).

 // Require a decimal point in the string being parsed:
 df.applyPattern("#.");
 df.setDecimalPatternMatchRequired(true);

 // Alternatively:
 df.setDecimalSeparatorAlwaysShown(true);
 df.setDecimalPatternMatchRequired(true);
 
To forbid a decimal point, call this method in combination with a pattern containing no decimal point. Alternatively, use setParseIntegerOnly(boolean) for the same behavior without depending on the contents of the pattern string.
 // Forbid a decimal point in the string being parsed:
 df.applyPattern("#");
 df.setDecimalPatternMatchRequired(true);
 

Parameters
value boolean: true to either require or forbid the decimal point according to the pattern; false to disable this feature.

setDecimalSeparatorAlwaysShown

Added in API level 24
public void setDecimalSeparatorAlwaysShown (boolean value)

Separators: Sets whether the decimal separator (a period in en-US) is shown on integers. For example, if this setting is turned on, formatting 123 will result in "123." with the decimal separator.

This setting can be specified in the pattern for integer formats: "#,##0." is an example.

Parameters
value boolean: true to always show the decimal separator; false to show it only when there is a fraction part of the number.

setExponentSignAlwaysShown

Added in API level 24
public void setExponentSignAlwaysShown (boolean expSignAlways)

[icu] Scientific Notation: Sets whether the sign (plus or minus) is always to be shown in the exponent in scientific notation. For example, if this setting is enabled, the number 123000 will be printed as "1.23E+5" in locale en-US. The number 0.0000123 will always be printed as "1.23E-5" in locale en-US whether or not this setting is enabled.

This setting corresponds to the '+' in a pattern such as "0.00E+0".

Parameters
expSignAlways boolean: true to always shown the sign in the exponent; false to show it for negatives but not positives.

setFormatWidth

Added in API level 24
public void setFormatWidth (int width)

Padding: Sets the minimum width of the string output by the formatting pipeline. For example, if padding is enabled and paddingWidth is set to 6, formatting the number "3.14159" with the pattern "0.00" will result in "··3.14" if '·' is your padding string.

If the number is longer than your padding width, the number will display as if no padding width had been specified, which may result in strings longer than the padding width.

Padding can be specified in the pattern string using the '*' symbol. For example, the format "*x######0" has a format width of 7 and a pad character of 'x'.

Padding is currently counted in UTF-16 code units; see ticket #13034 for more information.

Parameters
width int: The minimum number of characters in the output.

setGroupingSize

Added in API level 24
public void setGroupingSize (int width)

Grouping: Sets the primary grouping size (distance between grouping separators) used when formatting large numbers. For most locales, this defaults to 3: the number of digits between the ones and thousands place, between thousands and millions, and so forth.

For example, with a grouping size of 3, the number 1234567 will be formatted as "1,234,567".

Grouping size can also be specified in the pattern: for example, "#,##0" corresponds to a grouping size of 3.

Parameters
width int: The grouping size to use.

setGroupingUsed

Added in API level 24
public void setGroupingUsed (boolean enabled)

Grouping: Sets whether grouping is to be used when formatting numbers. Grouping means whether the thousands, millions, billions, and larger powers of ten should be separated by a grouping separator (a comma in en-US).

For example, if grouping is enabled, 12345 will be printed as "12,345" in en-US. If grouping were disabled, it would instead be printed as simply "12345".

Parameters
enabled boolean: true to enable grouping separators; false to disable them.

setMathContext

Added in API level 24
public void setMathContext (MathContext mathContext)

[icu] Rounding and Digit Limits: Sets the MathContext used to round numbers. A "math context" encodes both a rounding mode and a number of significant digits. Most users should call setRoundingMode(int) and/or setMaximumSignificantDigits(int) instead of this method.

When formatting, since no division is ever performed, the default MathContext is unlimited significant digits. However, when division occurs during parsing to correct for percentages and multipliers, a MathContext of 34 digits, the IEEE 754R Decimal128 standard, is used by default. If you require more than 34 digits when parsing, you can set a custom MathContext using this method.

Parameters
mathContext MathContext: The MathContext to use when rounding numbers.

Throws
ArithmeticException when inverting multiplier produces a non-terminating decimal result in conjunction with MathContext of unlimited precision.

See also:

setMathContextICU

Added in API level 24
public void setMathContextICU (MathContext mathContextICU)

[icu] Rounding and Digit Limits: Overload of setMathContext(MathContext) for MathContext.

Parameters
mathContextICU MathContext: The MathContext to use when rounding numbers.

Throws
ArithmeticException when inverting multiplier produces a non-terminating decimal result in conjunction with MathContext of unlimited precision.

setMaximumFractionDigits

Added in API level 24
public void setMaximumFractionDigits (int value)

Rounding and Digit Limits: Sets the maximum number of digits to display after the decimal separator. If the number has more than this many digits, the number is rounded according to the rounding mode.

For example, if maximum fraction digits is 2, the number 123.456 will be printed as "123.46".

Minimum integer and minimum and maximum fraction digits can be specified via the pattern string. For example, "#,#00.00#" has 2 minimum integer digits, 2 minimum fraction digits, and 3 maximum fraction digits. Note that it is not possible to specify maximum integer digits in the pattern except in scientific notation.

If minimum and maximum integer, fraction, or significant digits conflict with each other, the most recently specified value is used. For example, if there is a formatter with minInt=5, and then you set maxInt=3, then minInt will be changed to 3.

Parameters
value int: The maximum number of integer digits after the decimal separator.

setMaximumIntegerDigits

Added in API level 24
public void setMaximumIntegerDigits (int value)

Rounding and Digit Limits: Sets the maximum number of digits to display before the decimal separator. If the number has more than this many digits, the number is truncated.

For example, if maximum integer digits is 3, the number 12345 will be printed as "345".

Minimum integer and minimum and maximum fraction digits can be specified via the pattern string. For example, "#,#00.00#" has 2 minimum integer digits, 2 minimum fraction digits, and 3 maximum fraction digits. Note that it is not possible to specify maximum integer digits in the pattern except in scientific notation.

If minimum and maximum integer, fraction, or significant digits conflict with each other, the most recently specified value is used. For example, if there is a formatter with minInt=5, and then you set maxInt=3, then minInt will be changed to 3.

Parameters
value int: The maximum number of digits before the decimal separator.

setMaximumSignificantDigits

Added in API level 24
public void setMaximumSignificantDigits (int value)

[icu] Rounding and Digit Limits: Sets the maximum number of significant digits to be displayed. If the number of significant digits in the number exceeds this value, the number will be rounded according to the current rounding mode.

For example, if maximum significant digits is 3 and the number is 12345, the number will be printed as "12300".

If minimum and maximum integer, fraction, or significant digits conflict with each other, the most recently specified value is used. For example, if there is a formatter with minInt=5, and then you set maxInt=3, then minInt will be changed to 3.

See setRoundingIncrement(BigDecimal) and setMaximumFractionDigits(int) for two other ways of specifying rounding strategies.

Parameters
value int: The maximum number of significant digits to display.

setMinimumExponentDigits

Added in API level 24
public void setMinimumExponentDigits (byte minExpDig)

[icu] Scientific Notation: Sets the minimum number of digits to be printed in the exponent. For example, if minimum exponent digits is 3, the number 123000 will be printed as "1.23E005".

This setting corresponds to the number of zeros after the 'E' in a pattern string such as "0.00E000".

Parameters
minExpDig byte: The minimum number of digits in the exponent.

setMinimumFractionDigits

Added in API level 24
public void setMinimumFractionDigits (int value)

Rounding and Digit Limits: Sets the minimum number of digits to display after the decimal separator. If the number has fewer than this many digits, the number is padded with zeros.

For example, if minimum fraction digits is 2, the number 123.4 will be printed as "123.40".

Minimum integer and minimum and maximum fraction digits can be specified via the pattern string. For example, "#,#00.00#" has 2 minimum integer digits, 2 minimum fraction digits, and 3 maximum fraction digits. Note that it is not possible to specify maximum integer digits in the pattern except in scientific notation.

If minimum and maximum integer, fraction, or significant digits conflict with each other, the most recently specified value is used. For example, if there is a formatter with minInt=5, and then you set maxInt=3, then minInt will be changed to 3.

See setRoundingIncrement(BigDecimal) and setMaximumSignificantDigits(int) for two other ways of specifying rounding strategies.

Parameters
value int: The minimum number of integer digits after the decimal separator.

setMinimumGroupingDigits

Added in API level 31
public void setMinimumGroupingDigits (int number)

[icu] Sets the minimum number of digits that must be before the first grouping separator in order for the grouping separator to be printed. For example, if minimum grouping digits is set to 2, in en-US, 1234 will be printed as "1234" and 12345 will be printed as "12,345". Set the value to:

  • 1 to turn off minimum grouping digits.
  • MINIMUM_GROUPING_DIGITS_AUTO to display grouping using the default strategy for all locales.
  • MINIMUM_GROUPING_DIGITS_MIN2 to display grouping using locale defaults, except do not show grouping on values smaller than 10000 (such that there is a minimum of two digits before the first separator).

Parameters
number int: The minimum number of digits before grouping is triggered.

setMinimumIntegerDigits

Added in API level 24
public void setMinimumIntegerDigits (int value)

Rounding and Digit Limits: Sets the minimum number of digits to display before the decimal separator. If the number has fewer than this many digits, the number is padded with zeros.

For example, if minimum integer digits is 3, the number 12.3 will be printed as "001.23".

Minimum integer and minimum and maximum fraction digits can be specified via the pattern string. For example, "#,#00.00#" has 2 minimum integer digits, 2 minimum fraction digits, and 3 maximum fraction digits. Note that it is not possible to specify maximum integer digits in the pattern except in scientific notation.

If minimum and maximum integer, fraction, or significant digits conflict with each other, the most recently specified value is used. For example, if there is a formatter with minInt=5, and then you set maxInt=3, then minInt will be changed to 3.

Parameters
value int: The minimum number of digits before the decimal separator.

setMinimumSignificantDigits

Added in API level 24
public void setMinimumSignificantDigits (int value)

[icu] Rounding and Digit Limits: Sets the minimum number of significant digits to be displayed. If the number of significant digits is less than this value, the number will be padded with zeros as necessary.

For example, if minimum significant digits is 3 and the number is 1.2, the number will be printed as "1.20".

If minimum and maximum integer, fraction, or significant digits conflict with each other, the most recently specified value is used. For example, if there is a formatter with minInt=5, and then you set maxInt=3, then minInt will be changed to 3.

Parameters
value int: The minimum number of significant digits to display.

setMultiplier

Added in API level 24
public void setMultiplier (int multiplier)

Sets a number that will be used to multiply all numbers prior to formatting. For example, when formatting percents, a multiplier of 100 can be used.

If a percent or permille sign is specified in the pattern, the multiplier is automatically set to 100 or 1000, respectively.

If the number specified here is a power of 10, a more efficient code path will be used.

Parameters
multiplier int: The number by which all numbers passed to NumberFormat.format(BigDecimal) will be multiplied.

Throws
IllegalArgumentException If the given multiplier is zero.
ArithmeticException when inverting multiplier produces a non-terminating decimal result in conjunction with MathContext of unlimited precision.

setNegativePrefix

Added in API level 24
public void setNegativePrefix (String prefix)

Affixes: Sets the string to prepend to negative numbers. For example, if you set the value "#", then the number -123 will be formatted as "#123" in the locale en-US (overriding the implicit default '-' in the pattern).

Using this method overrides the affix specified via the pattern, and unlike the pattern, the string given to this method will be interpreted literally WITHOUT locale symbol substitutions.

Parameters
prefix String: The literal string to prepend to negative numbers.

setNegativeSuffix

Added in API level 24
public void setNegativeSuffix (String suffix)

Affixes: Sets the string to append to negative numbers. For example, if you set the value "#", then the number 123 will be formatted as "123#" in the locale en-US.

Using this method overrides the affix specified via the pattern, and unlike the pattern, the string given to this method will be interpreted literally WITHOUT locale symbol substitutions.

Parameters
suffix String: The literal string to append to negative numbers.

setPadCharacter

Added in API level 24
public void setPadCharacter (char padChar)

[icu] Padding: Sets the character used to pad numbers that are narrower than the width specified in setFormatWidth(int).

In the pattern string, the padding character is the token that follows '*' before or after the prefix or suffix.

Parameters
padChar char: The character used for padding.

setPadPosition

Added in API level 24
public void setPadPosition (int padPos)

[icu] Padding: Sets the position where to insert the pad character when narrower than the width specified in setFormatWidth(int). For example, consider the pattern "P123S" with padding width 8 and padding char "*". The four positions are:

Parameters
padPos int: The position used for padding.

setParseBigDecimal

Added in API level 24
public void setParseBigDecimal (boolean value)

Whether to make NumberFormat.parse(String) prefer returning a BigDecimal when possible. For strings corresponding to return values of Infinity, -Infinity, NaN, and -0.0, a Double will be returned even if ParseBigDecimal is enabled.

Parameters
value boolean: true to cause NumberFormat.parse(String) to prefer BigDecimal; false to let NumberFormat.parse(String) return additional data types like Long or BigInteger.

setParseCaseSensitive

Added in API level 31
public void setParseCaseSensitive (boolean value)

[icu] Specifies whether parsing should require cases to match in affixes, exponent separators, and currency codes. Case mapping is performed for each code point using UCharacter.foldCase(int, boolean).

Parameters
value boolean: true to force case (uppercase/lowercase) to match when parsing; false to ignore case and perform case folding.

setParseIntegerOnly

Added in API level 24
public void setParseIntegerOnly (boolean parseIntegerOnly)

Parsing: Sets whether to ignore the fraction part of a number when parsing (defaults to false). If a string contains a decimal point, parsing will stop before the decimal point. Note that determining whether a character is a decimal point depends on the locale.

For example, in en-US, parsing the string "123.45" will return the number 123 and parse position 3.

This is functionally equivalent to calling setDecimalPatternMatchRequired(boolean) and a pattern without a decimal point.

Parameters
parseIntegerOnly boolean: true to ignore fractional parts of numbers when parsing; false to consume fractional parts.

setParseMaxDigits

Added in API level 24
Deprecated in API level 28
public void setParseMaxDigits (int maxDigits)

This method was deprecated in API level 28.
Setting max parse digits has no effect since ICU4J 59.

Parameters
maxDigits int: Prior to ICU 59, the maximum number of digits in the output number after exponential notation is applied.

setParseNoExponent

Added in API level 31
public void setParseNoExponent (boolean value)

[icu] Specifies whether to stop parsing when an exponent separator is encountered. For example, parses "123E4" to 123 (with parse position 3) instead of 1230000 (with parse position 5).

Parameters
value boolean: true to prevent exponents from being parsed; false to allow them to be parsed.

setParseStrict

Added in API level 24
public void setParseStrict (boolean parseStrict)

[icu] Sets whether strict parsing is in effect. When this is true, the string is required to be a stronger match to the pattern than when lenient parsing is in effect. More specifically, the following conditions cause a parse failure relative to lenient mode (examples use the pattern "#,##0.#"):

  • The presence and position of special symbols, including currency, must match the pattern.
    '+123' fails (there is no plus sign in the pattern)
  • Leading or doubled grouping separators
    ',123' and '1,,234" fail
  • Groups of incorrect length when grouping is used
    '1,23' and '1234,567' fail, but '1234' passes
  • Grouping separators used in numbers followed by exponents
    '1,234E5' fails, but '1234E5' and '1,234E' pass ('E' is not an exponent when not followed by a number)
When strict parsing is off, all grouping separators are ignored. This is the default behavior.

Parameters
parseStrict boolean: True to enable strict parsing. Default is false.

setPositivePrefix

Added in API level 24
public void setPositivePrefix (String prefix)

Affixes: Sets the string to prepend to positive numbers. For example, if you set the value "#", then the number 123 will be formatted as "#123" in the locale en-US.

Using this method overrides the affix specified via the pattern, and unlike the pattern, the string given to this method will be interpreted literally WITHOUT locale symbol substitutions.

Parameters
prefix String: The literal string to prepend to positive numbers.

setPositiveSuffix

Added in API level 24
public void setPositiveSuffix (String suffix)

Affixes: Sets the string to append to positive numbers. For example, if you set the value "#", then the number 123 will be formatted as "123#" in the locale en-US.

Using this method overrides the affix specified via the pattern, and unlike the pattern, the string given to this method will be interpreted literally WITHOUT locale symbol substitutions.

Parameters
suffix String: The literal string to append to positive numbers.

setRoundingIncrement

Added in API level 24
public void setRoundingIncrement (BigDecimal increment)

[icu] Rounding and Digit Limits: Sets an increment, or interval, to which numbers are rounded. For example, a rounding increment of 0.05 will cause the number 1.23 to be rounded to 1.25 in the default rounding mode.

The rounding increment can be specified via the pattern string: for example, the pattern "#,##0.05" encodes a rounding increment of 0.05.

The rounding increment is applied after any multipliers might take effect; for example, in scientific notation or when setMultiplier(int) is used.

See setMaximumFractionDigits(int) and setMaximumSignificantDigits(int) for two other ways of specifying rounding strategies.

Parameters
increment BigDecimal: The increment to which numbers are to be rounded.

setRoundingIncrement

Added in API level 24
public void setRoundingIncrement (BigDecimal increment)

[icu] Rounding and Digit Limits: Overload of setRoundingIncrement(java.math.BigDecimal).

Parameters
increment BigDecimal: The increment to which numbers are to be rounded.

setRoundingIncrement

Added in API level 24
public void setRoundingIncrement (double increment)

[icu] Rounding and Digit Limits: Overload of setRoundingIncrement(java.math.BigDecimal).

Parameters
increment double: The increment to which numbers are to be rounded.

setRoundingMode

Added in API level 24
public void setRoundingMode (int roundingMode)

Rounding and Digit Limits: Sets the RoundingMode used to round numbers. The default rounding mode is HALF_EVEN, which rounds decimals to their closest whole number, and rounds to the closest even number if at the midpoint.

For more detail on rounding modes, see the ICU User Guide.

For backwards compatibility, the rounding mode is specified as an int argument, which can be from either the constants in BigDecimal or the ordinal value of RoundingMode. The following two calls are functionally equivalent.

 df.setRoundingMode(BigDecimal.ROUND_CEILING);
 df.setRoundingMode(RoundingMode.CEILING.ordinal());
 

Parameters
roundingMode int: The integer constant rounding mode to use when formatting numbers.

setScientificNotation

Added in API level 24
public void setScientificNotation (boolean useScientific)

[icu] Scientific Notation: Sets whether this formatter should print in scientific (exponential) notation. For example, if scientific notation is enabled, the number 123000 will be printed as "1.23E5" in locale en-US. A locale-specific symbol is used as the exponent separator.

Calling df.setScientificNotation(true) is functionally equivalent to calling df.setMinimumExponentDigits(1).

Parameters
useScientific boolean: true to enable scientific notation; false to disable it.

setSecondaryGroupingSize

Added in API level 24
public void setSecondaryGroupingSize (int width)

[icu] Grouping: Sets the secondary grouping size (distance between grouping separators after the first separator) used when formatting large numbers. In many south Asian locales, this is set to 2.

For example, with primary grouping size 3 and secondary grouping size 2, the number 1234567 will be formatted as "12,34,567".

Grouping size can also be specified in the pattern: for example, "#,##,##0" corresponds to a primary grouping size of 3 and a secondary grouping size of 2.

Parameters
width int: The secondary grouping size to use.

setSignAlwaysShown

Added in API level 31
public void setSignAlwaysShown (boolean value)

Sets whether to always shown the plus sign ('+' in en) on positive numbers. The rules in UTS #35 section 3.2.1 will be followed to ensure a locale-aware placement of the sign.

More specifically, the following strategy will be used to place the plus sign:

  1. Patterns without a negative subpattern: The locale's plus sign will be prepended to the positive prefix.
  2. Patterns with a negative subpattern without a '-' sign (e.g., accounting): The locale's plus sign will be prepended to the positive prefix, as in case 1.
  3. Patterns with a negative subpattern that has a '-' sign: The locale's plus sign will substitute the '-' in the negative subpattern. The positive subpattern will be unused.
This method is designed to be used instead of applying a pattern containing an explicit plus sign, such as "+0;-0". The behavior when combining this method with explicit plus signs in the pattern is undefined.

Parameters
value boolean: true to always show a sign; false to hide the sign on positive numbers and zero.

setSignificantDigitsUsed

Added in API level 24
public void setSignificantDigitsUsed (boolean useSignificantDigits)

[icu] Rounding and Digit Limits: Sets whether significant digits are to be used in rounding.

Calling df.setSignificantDigitsUsed(true) is functionally equivalent to:

 df.setMinimumSignificantDigits(1);
 df.setMaximumSignificantDigits(6);
 

Parameters
useSignificantDigits boolean: true to enable significant digit rounding; false to disable it.

toLocalizedPattern

Added in API level 24
public String toLocalizedPattern ()

Calls toPattern() and converts the string to localized notation. For more information on localized notation, see applyLocalizedPattern(String). This method is provided for backwards compatibility and should not be used in new projects.

Returns
String A decimal format pattern string in localized notation.

toPattern

Added in API level 24
public String toPattern ()

Serializes this formatter object to a decimal format pattern string. The result of this method is guaranteed to be functionally equivalent to the pattern string used to create this instance after incorporating values from the setter methods.

For more information on decimal format pattern strings, see UTS #35.

Important: Not all properties are capable of being encoded in a pattern string. See a list of properties in applyPattern(String).

Returns
String A decimal format pattern string.

toString

Added in API level 24
public String toString ()

Returns the default value of toString() with extra DecimalFormat-specific information appended to the end of the string. This extra information is intended for debugging purposes, and the format is not guaranteed to be stable.

Returns
String a string representation of the object.