DecimalFormat

public class DecimalFormat
extends NumberFormat

java.lang.Object
   ↳ java.text.Format
     ↳ java.text.NumberFormat
       ↳ java.text.DecimalFormat


DecimalFormat is a concrete subclass of NumberFormat that formats decimal numbers. It has a variety of features designed to make it possible to parse and format numbers in any locale, including support for Western, Arabic, and Indic digits. It also supports different kinds of numbers, including integers (123), fixed-point numbers (123.4), scientific notation (1.23E4), percentages (12%), and currency amounts ($123). All of these can be localized.

To obtain a NumberFormat for a specific locale, including the default locale, call one of NumberFormat's factory methods, such as getInstance(). In general, do not call the DecimalFormat constructors directly, since the NumberFormat factory methods may return subclasses other than DecimalFormat. If you need to customize the format object, do something like this:

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

A DecimalFormat comprises a pattern and a set of symbols. The pattern may be set directly using applyPattern(), or indirectly using the API methods. The symbols are stored in a DecimalFormatSymbols object. When using the NumberFormat factory methods, the pattern and symbols are read from localized ResourceBundles.

Patterns

DecimalFormat patterns have the following syntax:
 Pattern:
         PositivePattern
         PositivePattern ; NegativePattern
 PositivePattern:
         Prefixopt Number Suffixopt
 NegativePattern:
         Prefixopt Number Suffixopt
 Prefix:
         any Unicode characters except \uFFFE, \uFFFF, and special characters
 Suffix:
         any Unicode characters except \uFFFE, \uFFFF, and special characters
 Number:
         Integer Exponentopt
         Integer . Fraction Exponentopt
 Integer:
         MinimumInteger
         #
         # Integer
         # , Integer
 MinimumInteger:
         0
         0 MinimumInteger
         0 , MinimumInteger
 Fraction:
         MinimumFractionopt OptionalFractionopt
 MinimumFraction:
         0 MinimumFractionopt
 OptionalFraction:
         # OptionalFractionopt
 Exponent:
         E MinimumExponent
 MinimumExponent:
         0 MinimumExponentopt
 

A DecimalFormat pattern contains a positive and negative subpattern, for example, "#,##0.00;(#,##0.00)". Each subpattern has a prefix, numeric part, and suffix. The negative subpattern is optional; if absent, then the positive subpattern prefixed with the minus sign ('-' U+002D HYPHEN-MINUS) is used as the negative subpattern. That is, "0.00" alone is equivalent to "0.00;-0.00". If there is an explicit negative subpattern, it serves only to specify the negative prefix and suffix; the number of digits, minimal digits, and other characteristics are all the same as the positive pattern. That means that "#,##0.0#;(#)" produces precisely the same behavior as "#,##0.0#;(#,##0.0#)".

The prefixes, suffixes, and various symbols used for infinity, digits, grouping separators, decimal separators, etc. may be set to arbitrary values, and they will appear properly during formatting. However, care must be taken that the symbols and strings do not conflict, or parsing will be unreliable. For example, either the positive and negative prefixes or the suffixes must be distinct for DecimalFormat.parse() to be able to distinguish positive from negative values. (If they are identical, then DecimalFormat will behave as if no negative subpattern was specified.) Another example is that the decimal separator and grouping separator should be distinct characters, or parsing will be impossible.

The grouping separator is commonly used for thousands, but in some countries it separates ten-thousands. The grouping size is a constant number of digits between the grouping characters, such as 3 for 100,000,000 or 4 for 1,0000,0000. If you supply a pattern with multiple grouping characters, the interval between the last one and the end of the integer is the one that is used. So "#,##,###,####" == "######,####" == "##,####,####".

Special Pattern Characters

Many characters in a pattern are taken literally; they are matched during parsing and output unchanged during formatting. Special characters, on the other hand, stand for other characters, strings, or classes of characters. They must be quoted, unless noted otherwise, if they are to appear in the prefix or suffix as literals.

The characters listed here are used in non-localized patterns. Localized patterns use the corresponding characters taken from this formatter's DecimalFormatSymbols object instead, and these characters lose their special status. Two exceptions are the currency sign and quote, which are not localized.

Chart showing symbol, location, localized, and meaning.
Symbol Location Localized? Meaning
0 Number Yes Digit
# Number Yes Digit, zero shows as absent
. Number Yes Decimal separator or monetary decimal separator
- Number Yes Minus sign
, Number Yes Grouping separator or monetary grouping separator
E Number Yes Separates mantissa and exponent in scientific notation. Need not be quoted in prefix or suffix.
; Subpattern boundary Yes Separates positive and negative subpatterns
% Prefix or suffix Yes Multiply by 100 and show as percentage
\u2030 Prefix or suffix Yes Multiply by 1000 and show as per mille value
¤ (\u00A4) Prefix or suffix No Currency sign, replaced by currency symbol. If doubled, replaced by international currency symbol. If present in a pattern, the monetary decimal/grouping separators are used instead of the decimal/grouping separators.
' Prefix or suffix No Used to quote special characters in a prefix or suffix, for example, "'#'#" formats 123 to "#123". To create a single quote itself, use two in a row: "# o''clock".

Scientific Notation

Numbers in scientific notation are expressed as the product of a mantissa and a power of ten, for example, 1234 can be expressed as 1.234 x 10^3. The mantissa is often in the range 1.0 ≤ x < 10.0, but it need not be. DecimalFormat can be instructed to format and parse scientific notation only via a pattern; there is currently no factory method that creates a scientific notation format. In a pattern, the exponent character immediately followed by one or more digit characters indicates scientific notation. Example: "0.###E0" formats the number 1234 as "1.234E3".

  • The number of digit characters after the exponent character gives the minimum exponent digit count. There is no maximum. Negative exponents are formatted using the localized minus sign, not the prefix and suffix from the pattern. This allows patterns such as "0.###E0 m/s".
  • The minimum and maximum number of integer digits are interpreted together:
    • If the maximum number of integer digits is greater than their minimum number and greater than 1, it forces the exponent to be a multiple of the maximum number of integer digits, and the minimum number of integer digits to be interpreted as 1. The most common use of this is to generate engineering notation, in which the exponent is a multiple of three, e.g., "##0.#####E0". Using this pattern, the number 12345 formats to "12.345E3", and 123456 formats to "123.456E3".
    • Otherwise, the minimum number of integer digits is achieved by adjusting the exponent. Example: 0.00123 formatted with "00.###E0" yields "12.3E-4".
  • The number of significant digits in the mantissa is the sum of the minimum integer and maximum fraction digits, and is unaffected by the maximum integer digits. For example, 12345 formatted with "##0.##E0" is "12.3E3". To show all digits, set the significant digits count to zero. The number of significant digits does not affect parsing.
  • Exponential patterns may not contain grouping separators.

Rounding

DecimalFormat provides rounding modes defined in RoundingMode for formatting. By default, it uses RoundingMode.HALF_EVEN.

Digits

For formatting, DecimalFormat uses the ten consecutive characters starting with the localized zero digit defined in the DecimalFormatSymbols object as digits. For parsing, these digits as well as all Unicode decimal digits, as defined by Character.digit, are recognized.

Special Values

NaN is formatted as a string, which typically has a single character &#92;uFFFD. This string is determined by the DecimalFormatSymbols object. This is the only value for which the prefixes and suffixes are not used.

Infinity is formatted as a string, which typically has a single character &#92;u221E, with the positive or negative prefixes and suffixes applied. The infinity string is determined by the DecimalFormatSymbols object.

Negative zero ("-0") parses to

  • BigDecimal(0) if isParseBigDecimal() is true,
  • Long(0) if isParseBigDecimal() is false and isParseIntegerOnly() is true,
  • Double(-0.0) if both isParseBigDecimal() and isParseIntegerOnly() are false.

Synchronization

Decimal formats are generally not synchronized. It is recommended to create separate format instances for each thread. If multiple threads access a format concurrently, it must be synchronized externally.

Example

// Print out a number using the localized number, integer, currency,
 // and percent format for each localeLocale[] locales = NumberFormat.getAvailableLocales();
 double myNumber = -1234.56;
 NumberFormat form;
 for (int j = 0; j < 4; ++j) {
     System.out.println("FORMAT");
     for (int i = 0; i < locales.length; ++i) {
         if (locales[i].getCountry().length() == 0) {
            continue; // Skip language-only locales
         }
         System.out.print(locales[i].getDisplayName());
         switch (j) {
         case 0:
             form = NumberFormat.getInstance(locales[i]); break;
         case 1:
             form = NumberFormat.getIntegerInstance(locales[i]); break;
         case 2:
             form = NumberFormat.getCurrencyInstance(locales[i]); break;
         default:
             form = NumberFormat.getPercentInstance(locales[i]); break;
         }
         if (form instanceof DecimalFormat) {
             System.out.print(": " + ((DecimalFormat) form).toPattern());
         }
         System.out.print(" -> " + form.format(myNumber));
         try {
             System.out.println(" -> " + form.parse(form.format(myNumber)));
         } catch (ParseException e) {}
     }
 }
 

Summary

Inherited constants

Public constructors

DecimalFormat()

Creates a DecimalFormat using the default pattern and symbols for the default FORMAT locale.

DecimalFormat(String pattern)

Creates a DecimalFormat using the given pattern and the symbols for the default FORMAT locale.

DecimalFormat(String pattern, DecimalFormatSymbols symbols)

Creates a DecimalFormat using the given pattern and symbols.

Public methods

void applyLocalizedPattern(String pattern)

Apply the given pattern to this Format object.

void applyPattern(String pattern)

Apply the given pattern to this Format object.

Object clone()

Standard override; no change in semantics.

boolean equals(Object obj)

Overrides equals

final StringBuffer format(Object number, StringBuffer toAppendTo, FieldPosition pos)

Formats a number and appends the resulting text to the given string buffer.

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

Formats a double to produce a string.

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

Format a long to produce a string.

AttributedCharacterIterator formatToCharacterIterator(Object obj)

Formats an Object producing an AttributedCharacterIterator.

Currency getCurrency()

Gets the currency used by this decimal format when formatting currency values.

DecimalFormatSymbols getDecimalFormatSymbols()

Returns a copy of the decimal format symbols, which is generally not changed by the programmer or user.

int getGroupingSize()

Return the grouping size.

int getMaximumFractionDigits()

Gets the maximum number of digits allowed in the fraction portion of a number.

int getMaximumIntegerDigits()

Gets the maximum number of digits allowed in the integer portion of a number.

int getMinimumFractionDigits()

Gets the minimum number of digits allowed in the fraction portion of a number.

int getMinimumIntegerDigits()

Gets the minimum number of digits allowed in the integer portion of a number.

int getMultiplier()

Gets the multiplier for use in percent, per mille, and similar formats.

String getNegativePrefix()

Get the negative prefix.

String getNegativeSuffix()

Get the negative suffix.

String getPositivePrefix()

Get the positive prefix.

String getPositiveSuffix()

Get the positive suffix.

RoundingMode getRoundingMode()

Gets the RoundingMode used in this DecimalFormat.

int hashCode()

Overrides hashCode

boolean isDecimalSeparatorAlwaysShown()

Allows you to get the behavior of the decimal separator with integers.

boolean isGroupingUsed()

Returns true if grouping is used in this format.

boolean isParseBigDecimal()

Returns whether the parse(java.lang.String, java.text.ParsePosition) method returns BigDecimal.

boolean isParseIntegerOnly()

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

Number parse(String text, ParsePosition pos)

Parses text from a string to produce a Number.

void setCurrency(Currency currency)

Sets the currency used by this number format when formatting currency values.

void setDecimalFormatSymbols(DecimalFormatSymbols newSymbols)

Sets the decimal format symbols, which is generally not changed by the programmer or user.

void setDecimalSeparatorAlwaysShown(boolean newValue)

Allows you to set the behavior of the decimal separator with integers.

void setGroupingSize(int newValue)

Set the grouping size.

void setGroupingUsed(boolean newValue)

Set whether or not grouping will be used in this format.

void setMaximumFractionDigits(int newValue)

Sets the maximum number of digits allowed in the fraction portion of a number.

void setMaximumIntegerDigits(int newValue)

Sets the maximum number of digits allowed in the integer portion of a number.

void setMinimumFractionDigits(int newValue)

Sets the minimum number of digits allowed in the fraction portion of a number.

void setMinimumIntegerDigits(int newValue)

Sets the minimum number of digits allowed in the integer portion of a number.

void setMultiplier(int newValue)

Sets the multiplier for use in percent, per mille, and similar formats.

void setNegativePrefix(String newValue)

Set the negative prefix.

void setNegativeSuffix(String newValue)

Set the negative suffix.

void setParseBigDecimal(boolean newValue)

Sets whether the parse(java.lang.String, java.text.ParsePosition) method returns BigDecimal.

void setParseIntegerOnly(boolean value)

Sets whether or not numbers should be parsed as integers only.

void setPositivePrefix(String newValue)

Set the positive prefix.

void setPositiveSuffix(String newValue)

Set the positive suffix.

void setRoundingMode(RoundingMode roundingMode)

Sets the RoundingMode used in this DecimalFormat.

String toLocalizedPattern()

Synthesizes a localized pattern string that represents the current state of this Format object.

String toPattern()

Synthesizes a pattern string that represents the current state of this Format object.

Inherited methods

Public constructors

DecimalFormat

Added in API level 1
public DecimalFormat ()

Creates a DecimalFormat using the default pattern and symbols for the default FORMAT locale. This is a convenient way to obtain a DecimalFormat when internationalization is not the main concern.

To obtain standard formats for a given locale, use the factory methods on NumberFormat such as getNumberInstance. These factories will return the most appropriate sub-class of NumberFormat for a given locale.

DecimalFormat

Added in API level 1
public DecimalFormat (String pattern)

Creates a DecimalFormat using the given pattern and the symbols for the default FORMAT locale. This is a convenient way to obtain a DecimalFormat when internationalization is not the main concern.

To obtain standard formats for a given locale, use the factory methods on NumberFormat such as getNumberInstance. These factories will return the most appropriate sub-class of NumberFormat for a given locale.

Parameters
pattern String: a non-localized pattern string.

Throws
NullPointerException if pattern is null
IllegalArgumentException if the given pattern is invalid.

DecimalFormat

Added in API level 1
public DecimalFormat (String pattern, 
                DecimalFormatSymbols symbols)

Creates a DecimalFormat using the given pattern and symbols. Use this constructor when you need to completely customize the behavior of the format.

To obtain standard formats for a given locale, use the factory methods on NumberFormat such as getInstance or getCurrencyInstance. If you need only minor adjustments to a standard format, you can modify the format returned by a NumberFormat factory method.

Parameters
pattern String: a non-localized pattern string

symbols DecimalFormatSymbols: the set of symbols to be used

Throws
NullPointerException if any of the given arguments is null
IllegalArgumentException if the given pattern is invalid

Public methods

applyLocalizedPattern

Added in API level 1
public void applyLocalizedPattern (String pattern)

Apply the given pattern to this Format object. The pattern is assumed to be in a localized notation. A pattern is a short-hand specification for the various formatting properties. These properties can also be changed individually through the various setter methods.

There is no limit to integer digits set by this routine, since that is the typical end-user desire; use setMaximumInteger if you want to set a real value. For negative numbers, use a second pattern, separated by a semicolon

Example "#,#00.0#" → 1,234.56

This means a minimum of 2 integer digits, 1 fraction digit, and a maximum of 2 fraction digits.

Example: "#,#00.0#;(#,#00.0#)" for negatives in parentheses.

In negative patterns, the minimum and maximum counts are ignored; these are presumed to be set in the positive pattern.

Parameters
pattern String: a new pattern

Throws
NullPointerException if pattern is null
IllegalArgumentException if the given pattern is invalid.

applyPattern

Added in API level 1
public void applyPattern (String pattern)

Apply the given pattern to this Format object. A pattern is a short-hand specification for the various formatting properties. These properties can also be changed individually through the various setter methods.

There is no limit to integer digits set by this routine, since that is the typical end-user desire; use setMaximumInteger if you want to set a real value. For negative numbers, use a second pattern, separated by a semicolon

Example "#,#00.0#" → 1,234.56

This means a minimum of 2 integer digits, 1 fraction digit, and a maximum of 2 fraction digits.

Example: "#,#00.0#;(#,#00.0#)" for negatives in parentheses.

In negative patterns, the minimum and maximum counts are ignored; these are presumed to be set in the positive pattern.

Parameters
pattern String: a new pattern

Throws
NullPointerException if pattern is null
IllegalArgumentException if the given pattern is invalid.

clone

Added in API level 1
public Object clone ()

Standard override; no change in semantics.

Returns
Object a clone of this instance.

equals

Added in API level 1
public boolean equals (Object obj)

Overrides equals

Parameters
obj Object: the reference object with which to compare.

Returns
boolean true if this object is the same as the obj argument; false otherwise.

format

Added in API level 1
public final StringBuffer format (Object number, 
                StringBuffer toAppendTo, 
                FieldPosition pos)

Formats a number and appends the resulting text to the given string buffer. The number can be of any subclass of Number.

This implementation uses the maximum precision permitted.

Parameters
number Object: the number to format

toAppendTo StringBuffer: the StringBuffer to which the formatted text is to be appended

pos FieldPosition: keeps track on the position of the field within the returned string. For example, for formatting a number 1234567.89 in Locale.US locale, if the given fieldPosition is NumberFormat#INTEGER_FIELD, the begin index and end index of fieldPosition will be set to 0 and 9, respectively for the output string 1,234,567.89.

Returns
StringBuffer the value passed in as toAppendTo

Throws
IllegalArgumentException if number is null or not an instance of Number.
NullPointerException if toAppendTo or pos is null
ArithmeticException if rounding is needed with rounding mode being set to RoundingMode.UNNECESSARY

See also:

format

Added in API level 1
public StringBuffer format (double number, 
                StringBuffer result, 
                FieldPosition fieldPosition)

Formats a double to produce a string.

Parameters
number double: The double to format

result StringBuffer: where the text is to be appended

fieldPosition FieldPosition: keeps track on the position of the field within the returned string. For example, for formatting a number 1234567.89 in Locale.US locale, if the given fieldPosition is NumberFormat#INTEGER_FIELD, the begin index and end index of fieldPosition will be set to 0 and 9, respectively for the output string 1,234,567.89.

Returns
StringBuffer The formatted number string

Throws
NullPointerException if result or fieldPosition is null
ArithmeticException if rounding is needed with rounding mode being set to RoundingMode.UNNECESSARY

See also:

format

Added in API level 1
public StringBuffer format (long number, 
                StringBuffer result, 
                FieldPosition fieldPosition)

Format a long to produce a string.

Parameters
number long: The long to format

result StringBuffer: where the text is to be appended

fieldPosition FieldPosition: keeps track on the position of the field within the returned string. For example, for formatting a number 123456789 in Locale.US locale, if the given fieldPosition is NumberFormat#INTEGER_FIELD, the begin index and end index of fieldPosition will be set to 0 and 11, respectively for the output string 123,456,789.

Returns
StringBuffer The formatted number string

Throws
NullPointerException if result or fieldPosition is null
ArithmeticException if rounding is needed with rounding mode being set to RoundingMode.UNNECESSARY

See also:

formatToCharacterIterator

Added in API level 1
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 NumberFormat.Field, with the attribute value being the same as the attribute key.

Parameters
obj Object: The object to format

Returns
AttributedCharacterIterator AttributedCharacterIterator describing the formatted value.

Throws
NullPointerException if obj is null.
IllegalArgumentException when the Format cannot format the given object.
ArithmeticException if rounding is needed with rounding mode being set to RoundingMode.UNNECESSARY

getCurrency

Added in API level 1
public Currency getCurrency ()

Gets the currency used by this decimal format when formatting currency values. The currency is obtained by calling DecimalFormatSymbols.getCurrency on this number format's symbols.

Returns
Currency the currency used by this decimal format, or null

getDecimalFormatSymbols

Added in API level 1
public DecimalFormatSymbols getDecimalFormatSymbols ()

Returns a copy of the decimal format symbols, which is generally not changed by the programmer or user.

Returns
DecimalFormatSymbols a copy of the desired DecimalFormatSymbols

getGroupingSize

Added in API level 1
public int getGroupingSize ()

Return the grouping size. Grouping size is the number of digits between grouping separators in the integer portion of a number. For example, in the number "123,456.78", the grouping size is 3. Grouping size of zero designates that grouping is not used, which provides the same formatting as if calling setGroupingUsed(false).

Returns
int the grouping size

getMaximumFractionDigits

Added in API level 1
public int getMaximumFractionDigits ()

Gets the maximum number of digits allowed in the fraction portion of a number. For formatting numbers other than BigInteger and BigDecimal objects, the lower of the return value and 340 is used.

Returns
int the maximum number of digits.

getMaximumIntegerDigits

Added in API level 1
public int getMaximumIntegerDigits ()

Gets the maximum number of digits allowed in the integer portion of a number. For formatting numbers other than BigInteger and BigDecimal objects, the lower of the return value and 309 is used.

Returns
int the maximum number of digits

getMinimumFractionDigits

Added in API level 1
public int getMinimumFractionDigits ()

Gets the minimum number of digits allowed in the fraction portion of a number. For formatting numbers other than BigInteger and BigDecimal objects, the lower of the return value and 340 is used.

Returns
int the minimum number of digits

getMinimumIntegerDigits

Added in API level 1
public int getMinimumIntegerDigits ()

Gets the minimum number of digits allowed in the integer portion of a number. For formatting numbers other than BigInteger and BigDecimal objects, the lower of the return value and 309 is used.

Returns
int the minimum number of digits

getMultiplier

Added in API level 1
public int getMultiplier ()

Gets the multiplier for use in percent, per mille, and similar formats.

Returns
int the multiplier

See also:

getNegativePrefix

Added in API level 1
public String getNegativePrefix ()

Get the negative prefix.

Examples: -123, ($123) (with negative suffix), sFr-123

Returns
String the negative prefix

getNegativeSuffix

Added in API level 1
public String getNegativeSuffix ()

Get the negative suffix.

Examples: -123%, ($123) (with positive suffixes)

Returns
String the negative suffix

getPositivePrefix

Added in API level 1
public String getPositivePrefix ()

Get the positive prefix.

Examples: +123, $123, sFr123

Returns
String the positive prefix

getPositiveSuffix

Added in API level 1
public String getPositiveSuffix ()

Get the positive suffix.

Example: 123%

Returns
String the positive suffix

getRoundingMode

Added in API level 9
public RoundingMode getRoundingMode ()

Gets the RoundingMode used in this DecimalFormat.

Returns
RoundingMode The RoundingMode used for this DecimalFormat.

hashCode

Added in API level 1
public int hashCode ()

Overrides hashCode

Returns
int a hash code value for this object.

isDecimalSeparatorAlwaysShown

Added in API level 1
public boolean isDecimalSeparatorAlwaysShown ()

Allows you to get the behavior of the decimal separator with integers. (The decimal separator will always appear with decimals.)

Example: Decimal ON: 12345 → 12345.; OFF: 12345 → 12345

Returns
boolean true if the decimal separator is always shown; false otherwise

isGroupingUsed

Added in API level 1
public boolean isGroupingUsed ()

Returns true if grouping is used in this format. For example, in the English locale, with grouping on, the number 1234567 might be formatted as "1,234,567". The grouping separator as well as the size of each group is locale dependent and is determined by sub-classes of NumberFormat.

Returns
boolean true if grouping is used; false otherwise

isParseBigDecimal

Added in API level 1
public boolean isParseBigDecimal ()

Returns whether the parse(java.lang.String, java.text.ParsePosition) method returns BigDecimal. The default value is false.

Returns
boolean true if the parse method returns BigDecimal; false otherwise

isParseIntegerOnly

Added in API level 1
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. Of course, the exact format accepted by the parse operation is locale dependent and determined by sub-classes of NumberFormat.

Returns
boolean true if numbers should be parsed as integers only; false otherwise

parse

Added in API level 1
public Number parse (String text, 
                ParsePosition pos)

Parses text from a string to produce a Number.

The method attempts to parse text starting at the index given by pos. If parsing succeeds, then the index of pos is updated to the index after the last character used (parsing does not necessarily use all characters up to the end of the string), and the parsed number is returned. The updated pos can be used to indicate the starting point for the next call to this method. If an error occurs, then the index of pos is not changed, the error index of pos is set to the index of the character where the error occurred, and null is returned.

The subclass returned depends on the value of isParseBigDecimal() as well as on the string being parsed.

  • If isParseBigDecimal() is false (the default), most integer values are returned as Long objects, no matter how they are written: "17" and "17.000" both parse to Long(17). Values that cannot fit into a Long are returned as Doubles. This includes values with a fractional part, infinite values, NaN, and the value -0.0. DecimalFormat does not decide whether to return a Double or a Long based on the presence of a decimal separator in the source string. Doing so would prevent integers that overflow the mantissa of a double, such as "-9,223,372,036,854,775,808.00", from being parsed accurately.

    Callers may use the Number methods doubleValue, longValue, etc., to obtain the type they want.

  • If isParseBigDecimal() is true, values are returned as BigDecimal objects. The values are the ones constructed by BigDecimal.BigDecimal(String) for corresponding strings in locale-independent format. The special cases negative and positive infinity and NaN are returned as Double instances holding the values of the corresponding Double constants.

DecimalFormat parses all Unicode characters that represent decimal digits, as defined by Character.digit(). In addition, DecimalFormat also recognizes as digits the ten consecutive characters starting with the localized zero digit defined in the DecimalFormatSymbols object.

Parameters
text String: the string to be parsed

pos ParsePosition: A ParsePosition object with index and error index information as described above.

Returns
Number the parsed value, or null if the parse fails

Throws
NullPointerException if text or pos is null.

setCurrency

Added in API level 1
public void setCurrency (Currency currency)

Sets the currency used by this number format when formatting currency values. This does not update the minimum or maximum number of fraction digits used by the number format. The currency is set by calling DecimalFormatSymbols.setCurrency on this number format's symbols.

Parameters
currency Currency: the new currency to be used by this decimal format

Throws
NullPointerException if currency is null

setDecimalFormatSymbols

Added in API level 1
public void setDecimalFormatSymbols (DecimalFormatSymbols newSymbols)

Sets the decimal format symbols, which is generally not changed by the programmer or user.

Parameters
newSymbols DecimalFormatSymbols: desired DecimalFormatSymbols

setDecimalSeparatorAlwaysShown

Added in API level 1
public void setDecimalSeparatorAlwaysShown (boolean newValue)

Allows you to set the behavior of the decimal separator with integers. (The decimal separator will always appear with decimals.)

Example: Decimal ON: 12345 → 12345.; OFF: 12345 → 12345

Parameters
newValue boolean: true if the decimal separator is always shown; false otherwise

setGroupingSize

Added in API level 1
public void setGroupingSize (int newValue)

Set the grouping size. Grouping size is the number of digits between grouping separators in the integer portion of a number. For example, in the number "123,456.78", the grouping size is 3. Grouping size of zero designates that grouping is not used, which provides the same formatting as if calling setGroupingUsed(false).

The value passed in is converted to a byte, which may lose information. Values that are negative or greater than Byte.MAX_VALUE, will throw an IllegalArgumentException.

Parameters
newValue int: the new grouping size

Throws
IllegalArgumentException if newValue is negative or greater than Byte.MAX_VALUE

setGroupingUsed

Added in API level 1
public void setGroupingUsed (boolean newValue)

Set whether or not grouping will be used in this format.

Parameters
newValue boolean: true if grouping is used; false otherwise

setMaximumFractionDigits

Added in API level 1
public void setMaximumFractionDigits (int newValue)

Sets the maximum number of digits allowed in the fraction portion of a number. For formatting numbers other than BigInteger and BigDecimal objects, the lower of newValue and 340 is used. Negative input values are replaced with 0.

Parameters
newValue int: the maximum number of fraction digits to be shown; if less than zero, then zero is used. The concrete subclass may enforce an upper limit to this value appropriate to the numeric type being formatted.

setMaximumIntegerDigits

Added in API level 1
public void setMaximumIntegerDigits (int newValue)

Sets the maximum number of digits allowed in the integer portion of a number. For formatting numbers other than BigInteger and BigDecimal objects, the lower of newValue and 309 is used. Negative input values are replaced with 0.

Parameters
newValue int: the maximum number of integer digits to be shown; if less than zero, then zero is used. The concrete subclass may enforce an upper limit to this value appropriate to the numeric type being formatted.

setMinimumFractionDigits

Added in API level 1
public void setMinimumFractionDigits (int newValue)

Sets the minimum number of digits allowed in the fraction portion of a number. For formatting numbers other than BigInteger and BigDecimal objects, the lower of newValue and 340 is used. Negative input values are replaced with 0.

Parameters
newValue int: the minimum number of fraction digits to be shown; if less than zero, then zero is used. The concrete subclass may enforce an upper limit to this value appropriate to the numeric type being formatted.

setMinimumIntegerDigits

Added in API level 1
public void setMinimumIntegerDigits (int newValue)

Sets the minimum number of digits allowed in the integer portion of a number. For formatting numbers other than BigInteger and BigDecimal objects, the lower of newValue and 309 is used. Negative input values are replaced with 0.

Parameters
newValue int: the minimum number of integer digits to be shown; if less than zero, then zero is used. The concrete subclass may enforce an upper limit to this value appropriate to the numeric type being formatted.

setMultiplier

Added in API level 1
public void setMultiplier (int newValue)

Sets the multiplier for use in percent, per mille, and similar formats. For a percent format, set the multiplier to 100 and the suffixes to have '%' (for Arabic, use the Arabic percent sign). For a per mille format, set the multiplier to 1000 and the suffixes to have '\u2030'.

Example: with multiplier 100, 1.23 is formatted as "123", and "123" is parsed into 1.23.

Parameters
newValue int: the new multiplier

See also:

setNegativePrefix

Added in API level 1
public void setNegativePrefix (String newValue)

Set the negative prefix.

Examples: -123, ($123) (with negative suffix), sFr-123

Parameters
newValue String: the new negative prefix

setNegativeSuffix

Added in API level 1
public void setNegativeSuffix (String newValue)

Set the negative suffix.

Examples: 123%

Parameters
newValue String: the new negative suffix

setParseBigDecimal

Added in API level 1
public void setParseBigDecimal (boolean newValue)

Sets whether the parse(java.lang.String, java.text.ParsePosition) method returns BigDecimal.

Parameters
newValue boolean: true if the parse method returns BigDecimal; false otherwise

setParseIntegerOnly

Added in API level 1
public void setParseIntegerOnly (boolean value)

Sets whether or not numbers should be parsed as integers only.

Parameters
value boolean: true if numbers should be parsed as integers only; false otherwise

setPositivePrefix

Added in API level 1
public void setPositivePrefix (String newValue)

Set the positive prefix.

Examples: +123, $123, sFr123

Parameters
newValue String: the new positive prefix

setPositiveSuffix

Added in API level 1
public void setPositiveSuffix (String newValue)

Set the positive suffix.

Example: 123%

Parameters
newValue String: the new positive suffix

setRoundingMode

Added in API level 9
public void setRoundingMode (RoundingMode roundingMode)

Sets the RoundingMode used in this DecimalFormat.

Parameters
roundingMode RoundingMode: The RoundingMode to be used

Throws
NullPointerException if roundingMode is null.

See also:

toLocalizedPattern

Added in API level 1
public String toLocalizedPattern ()

Synthesizes a localized pattern string that represents the current state of this Format object.

Returns
String a localized pattern string

toPattern

Added in API level 1
public String toPattern ()

Synthesizes a pattern string that represents the current state of this Format object.

Returns
String a pattern string