# Class CompactNumberFormat

java.lang.Object
java.text.Format
java.text.NumberFormat
java.text.CompactNumberFormat

All Implemented Interfaces:
  `Serializable`, `Cloneable`

public final class CompactNumberFormat extends NumberFormat

`CompactNumberFormat` is a concrete subclass of `NumberFormat` that formats a decimal number in a localized compact form. Compact number formatting is designed for an environment with limited space. For example, displaying the formatted number `7M` instead of `7,000,000.00` in the `US locale`. The `CompactNumberFormat` class is defined by LDML's specification for Compact Number Formats.

## Getting a CompactNumberFormat

To get a compact number format, use one of the ways listed below.

- Use the factory method `NumberFormat.getCompactNumberInstance()` to obtain a format for the default locale with `SHORT` style.
- Use the factory methood `NumberFormat.getCompactNumberInstance(Locale, Style)` to obtain a format for a different locale and to control the Style.
- Use one of the `CompactNumberFormat` constructors, for example, `CompactNumberFormat(decimalPattern, symbols, compactPatterns)`, to obtain a `CompactNumberFormat` with further customization.

If a standard compact format for a given locale and `style` is desired, it is recommended to use one of the NumberFormat factory methods listed above. To use an instance method defined by `CompactNumberFormat`, the `NumberFormat` returned by these factory methods should be type checked before converted to `CompactNumberFormat`. If the installed locale-sensitive service implementation does not support the given `Locale`, the parent locale chain will be looked up, and a `Locale` used that is supported.

## Style

When using `NumberFormat.getCompactNumberInstance(Locale, Style)`, a compact form can be retrieved with either a `SHORT` or `LONG` style. For example, a `SHORT` style compact number instance in the `US locale` formats `10000` as `"10K"`. However, a `LONG` style instance in the same locale formats `10000` as `"10 thousand"`.

## Using CompactNumberFormat

The following is an example of formatting and parsing in a localized manner,

    NumberFormat compactFormat = NumberFormat.getCompactNumberInstance(Locale.US, NumberFormat.Style.SHORT);
    compactFormat.format(1000); // returns "1K"
    compactFormat.parse("1K"); // returns 1000

## Formatting

The default formatting behavior returns a formatted string with no fractional digits, however users can use the `setMinimumFractionDigits(int)` method to include the fractional part. The number `1000.0` or `1000` is formatted as `"1K"` not `"1.00K"` (in the `US locale`). For this reason, the patterns provided for formatting contain only the minimum integer digits, prefix and/or suffix, but no fractional part. For example, patterns used are `{"", "", "", 0K, 00K, ...}`. If the pattern selected for formatting a number is `"0"` (special pattern), either explicit or defaulted, then the general number formatting provided by `DecimalFormat` for the specified locale is used.

### Rounding

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

## Parsing

The default parsing behavior does not allow a grouping separator until grouping used is set to `true` by using `setGroupingUsed(boolean)`. The parsing of the fractional part depends on the `isParseIntegerOnly()`. For example, if the parse integer only is set to true, then the fractional part is skipped.

## Compact Number Patterns

The `compactPatterns` in `CompactNumberFormat(decimalPattern, symbols, compactPatterns)` are represented as a series of strings, where each string is a `pattern` that is used to format a range of numbers.

An example of the `SHORT` styled compact number patterns for the `US locale` is `{"", "", "", "0K", "00K", "000K", "0M", "00M", "000M", "0B", "00B", "000B", "0T", "00T", "000T"}`, ranging from `10``0` to `10``14`. There can be any number of patterns and they are strictly index based starting from the range `10``0`. For example, in the above patterns, the pattern at index 3 (`"0K"`) is used for formatting a number in the range: `1000 <= number < 10000`, index 4 (`"00K"`) for formatting a number the range: `10000 <= number < 100000`, and so forth.

In most locales, patterns with the range `10``0`-`10``2` are empty strings, which implicitly means a special pattern `"0"`. A special pattern `"0"` is used for any range which does not contain a compact pattern. This special pattern can appear explicitly for any specific range, or considered as a default pattern for an empty string.

### Negative Subpatterns

A compact pattern contains a positive and negative subpattern separated by a subpattern boundary character `';'`, for example, `"0K;-0K"`. Each subpattern has a prefix, minimum integer digits, 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, `"0K"` alone is equivalent to `"0K;-0K"`. If there is an explicit negative subpattern, it serves only to specify the negative prefix and suffix. The number of minimum integer digits, and other characteristics are all the same as the positive pattern. That means that `"0K;-00K"` produces precisely the same behavior as `"0K;-0K"`.

#### Escaping Special Characters

Many characters in a compact 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. These characters must be quoted using single quotes `' (U+0027)` unless noted otherwise, if they are to appear in the prefix or suffix as literals. For example, 0क'.'.

### Plurals

`CompactNumberFormat` support patterns for both singular and plural compact forms. For the plural form, the `Pattern` should consist of `PluralPattern`(s) separated by a space ' ' (U+0020) that are enumerated within a pair of curly brackets '{' (U+007B) and '}' (U+007D). In this format, each `PluralPattern` consists of its `count`, followed by a single colon `':' (U+003A)` and a `SimplePattern`. As a space is reserved for separating subsequent `PluralPattern`s, it must be quoted to be used literally in either the `prefix` or `suffix`.

For example, while the pattern representing millions (`10``6` ) in the US locale can be specified as the SimplePattern: `"0 Million"`, for the German locale it can be specified as the PluralPattern: `"{one:0' 'Million other:0' 'Millionen}"`.

A compact pattern has the following syntax, with `count` following LDML's Language Plural Rules:

>      Pattern:
>              SimplePattern
>              '{' PluralPattern [' ' PluralPattern]optional '}'
>      SimplePattern:
>              PositivePattern
>              PositivePattern [; NegativePattern]optional
>      PluralPattern:
>              Count:SimplePattern
>      Count:
>              "zero" / "one" / "two" / "few" / "many" / "other"
>      PositivePattern:
>              Prefixoptional MinimumInteger Suffixoptional
>      NegativePattern:
>             Prefixoptional MinimumInteger Suffixoptional
>      Prefix:
>           Any characters except the special pattern characters
>      Suffix:
>           Any characters except the special pattern characters
>      MinimumInteger:
>           0
>           0 MinimumInteger

Since:
  12
External Specifications
  - Unicode Locale Data Markup Language (LDML)
See Also:
  - `NumberFormat.Style`
  - `NumberFormat`
  - `DecimalFormat`
  - `Locale`
  - Serialized Form

- ## Nested Class Summary

  ### Nested classes/interfaces declared in class java.text.NumberFormat

  `NumberFormat.Field, NumberFormat.Style`

- ## Field Summary

  ### Fields declared in class java.text.NumberFormat

  `FRACTION_FIELD, INTEGER_FIELD`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `CompactNumberFormat(String decimalPattern, DecimalFormatSymbols symbols, String[] compactPatterns)`
  Creates a `CompactNumberFormat` using the given decimal pattern, decimal format symbols and compact patterns.
  `CompactNumberFormat(String decimalPattern, DecimalFormatSymbols symbols, String[] compactPatterns, String pluralRules)`
  Creates a `CompactNumberFormat` using the given decimal pattern, decimal format symbols, compact patterns, and plural rules.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `CompactNumberFormat`
  `clone()`
  Creates and returns a copy of this `CompactNumberFormat` instance.
  `boolean`
  `equals(Object obj)`
  Compares the specified object with this `CompactNumberFormat` for equality.
  `StringBuffer`
  `format(double number, StringBuffer result, FieldPosition fieldPosition)`
  Formats a double to produce a string representing its compact form.
  `StringBuffer`
  `format(long number, StringBuffer result, FieldPosition fieldPosition)`
  Formats a long to produce a string representing its compact form.
  `final StringBuffer`
  `format(Object number, StringBuffer toAppendTo, FieldPosition fieldPosition)`
  Formats a number to produce a string representing its compact form.
  `AttributedCharacterIterator`
  `formatToCharacterIterator(Object obj)`
  Formats an Object producing an `AttributedCharacterIterator`.
  `int`
  `getGroupingSize()`
  Returns the grouping size.
  `RoundingMode`
  `getRoundingMode()`
  Gets the `RoundingMode` used in this `CompactNumberFormat`.
  `int`
  `hashCode()`
  Returns the hash code for this `CompactNumberFormat`.
  `boolean`
  `isGroupingUsed()`
  Returns true if grouping is used in this format.
  `boolean`
  `isParseBigDecimal()`
  Returns whether the `parse(String, ParsePosition)` method returns `BigDecimal`.
  `boolean`
  `isParseIntegerOnly()`
  Returns true if this format parses only an integer from the number component of a compact number.
  `boolean`
  `isStrict()`
  Returns `true` if this format will parse numbers strictly; `false` otherwise.
  `Number`
  `parse(String text, ParsePosition pos)`
  Parses text from the beginning of the given string to produce a `Number`.
  `void`
  `setGroupingSize(int newValue)`
  Sets the grouping size.
  `void`
  `setGroupingUsed(boolean newValue)`
  Sets 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`
  `setParseBigDecimal(boolean newValue)`
  Sets whether the `parse(String, ParsePosition)` method returns `BigDecimal`.
  `void`
  `setParseIntegerOnly(boolean value)`
  Sets whether or not this format parses only an integer from the number component of a compact number.
  `void`
  `setRoundingMode(RoundingMode roundingMode)`
  Sets the `RoundingMode` used in this `CompactNumberFormat`.
  `void`
  `setStrict(boolean strict)`
  Change the leniency value for parsing.
  `String`
  `toString()`
  Returns a string identifying this `CompactNumberFormat`, for debugging.

  ### Methods declared in class java.text.NumberFormat

  `format, format, getAvailableLocales, getCompactNumberInstance, getCompactNumberInstance, getCurrency, getCurrencyInstance, getCurrencyInstance, getInstance, getInstance, getIntegerInstance, getIntegerInstance, getMaximumFractionDigits, getMaximumIntegerDigits, getMinimumFractionDigits, getMinimumIntegerDigits, getNumberInstance, getNumberInstance, getPercentInstance, getPercentInstance, parse, parseObject, setCurrency`

  ### Methods declared in class java.text.Format

  `format, parseObject`

  ### Methods declared in class java.lang.Object

  `finalize, getClass, notify, notifyAll, wait, wait, wait`

- ## Constructor Details

  - ### CompactNumberFormat

    public CompactNumberFormat(String decimalPattern, DecimalFormatSymbols symbols, String[] compactPatterns)
    Creates a `CompactNumberFormat` using the given decimal pattern, decimal format symbols and compact patterns. To obtain the instance of `CompactNumberFormat` with the standard compact patterns for a `Locale` and `Style`, it is recommended to use the factory methods given by `NumberFormat` for compact number formatting.

    Below is an example of using the constructor,

        String[] compactPatterns = {"", "", "", "a lot"};
        NumberFormat fmt = new CompactNumberFormat("00", DecimalFormatSymbols.getInstance(Locale.US), compactPatterns);
        fmt.format(1); // returns "01"
        fmt.format(1000); // returns "a lot"

    Parameters:
      `decimalPattern` - a decimal pattern for general number formatting
      `symbols` - the set of symbols to be used
      `compactPatterns` - an array of compact number patterns
    Throws:
      `NullPointerException` - if any of the given arguments is `null`
      `IllegalArgumentException` - if the given `decimalPattern` or the `compactPatterns` array contains an invalid pattern or if a `null` appears in the array of compact patterns
    See Also:
      - `DecimalFormat(java.lang.String, DecimalFormatSymbols)`
      - `DecimalFormatSymbols`

  - ### CompactNumberFormat

    public CompactNumberFormat(String decimalPattern, DecimalFormatSymbols symbols, String[] compactPatterns, String pluralRules)
    Creates a `CompactNumberFormat` using the given decimal pattern, decimal format symbols, compact patterns, and plural rules. To obtain the instance of `CompactNumberFormat` with the standard compact patterns for a `Locale`, `Style`, and `pluralRules`, it is recommended to use the factory methods given by `NumberFormat` for compact number formatting. For example, `NumberFormat.getCompactNumberInstance(Locale, Style)`.
    Parameters:
      `decimalPattern` - a decimal pattern for general number formatting
      `symbols` - the set of symbols to be used
      `compactPatterns` - an array of compact number patterns
      `pluralRules` - a String designating plural rules which associate the `Count` keyword, such as "`one`", and the actual integer number. Its syntax is defined in Unicode Consortium's Plural rules syntax
    Throws:
      `NullPointerException` - if any of the given arguments is `null`
      `IllegalArgumentException` - if the given `decimalPattern`, the `compactPatterns` array contains an invalid pattern, a `null` appears in the array of compact patterns, or if the given `pluralRules` contains an invalid syntax
    Since:
      14
    External Specifications
      - Unicode Locale Data Markup Language (LDML)
    See Also:
      - `DecimalFormat(java.lang.String, DecimalFormatSymbols)`
      - `DecimalFormatSymbols`

- ## Method Details

  - ### format

    public final StringBuffer format(Object number, StringBuffer toAppendTo, FieldPosition fieldPosition)
    Formats a number to produce a string representing its compact form. The number can be of any subclass of `Number`.
    Overrides:
      `format` in class `NumberFormat`
    Parameters:
      `number` - the number to format
      `toAppendTo` - the `StringBuffer` to which the formatted text is to be appended
      `fieldPosition` - keeps track on the position of the field within the returned string. For example, for formatting a number `123456789` in the `US locale`, if the given `fieldPosition` is `NumberFormat.INTEGER_FIELD`, the begin index and end index of `fieldPosition` will be set to 0 and 3, respectively for the output string `123M`. Similarly, positions of the prefix and the suffix fields can be obtained using `NumberFormat.Field.PREFIX` and `NumberFormat.Field.SUFFIX` respectively.
    Returns:
      the `StringBuffer` passed in as `toAppendTo`
    Throws:
      `IllegalArgumentException` - if `number` is `null` or not an instance of `Number`
      `NullPointerException` - if `toAppendTo` or `fieldPosition` is `null`
      `ArithmeticException` - if rounding is needed with rounding mode being set to `RoundingMode.UNNECESSARY`
    See Also:
      - `FieldPosition`

  - ### format

    public StringBuffer format(double number, StringBuffer result, FieldPosition fieldPosition)
    Formats a double to produce a string representing its compact form.
    Specified by:
      `format` in class `NumberFormat`
    Parameters:
      `number` - the double number to format
      `result` - where the text is to be appended
      `fieldPosition` - keeps track on the position of the field within the returned string. For example, to format a number `1234567.89` in the `US locale` if the given `fieldPosition` is `NumberFormat.INTEGER_FIELD`, the begin index and end index of `fieldPosition` will be set to 0 and 1, respectively for the output string `1M`. Similarly, positions of the prefix and the suffix fields can be obtained using `NumberFormat.Field.PREFIX` and `NumberFormat.Field.SUFFIX` respectively.
    Returns:
      the `StringBuffer` passed in as `result`
    Throws:
      `NullPointerException` - if `result` or `fieldPosition` is `null`
      `ArithmeticException` - if rounding is needed with rounding mode being set to `RoundingMode.UNNECESSARY`
    See Also:
      - `FieldPosition`

  - ### format

    public StringBuffer format(long number, StringBuffer result, FieldPosition fieldPosition)
    Formats a long to produce a string representing its compact form.
    Specified by:
      `format` in class `NumberFormat`
    Parameters:
      `number` - the long number to format
      `result` - where the text is to be appended
      `fieldPosition` - keeps track on the position of the field within the returned string. For example, to format a number `123456789` in the `US locale`, if the given `fieldPosition` is `NumberFormat.INTEGER_FIELD`, the begin index and end index of `fieldPosition` will be set to 0 and 3, respectively for the output string `123M`. Similarly, positions of the prefix and the suffix fields can be obtained using `NumberFormat.Field.PREFIX` and `NumberFormat.Field.SUFFIX` respectively.
    Returns:
      the `StringBuffer` passed in as `result`
    Throws:
      `NullPointerException` - if `result` or `fieldPosition` is `null`
      `ArithmeticException` - if rounding is needed with rounding mode being set to `RoundingMode.UNNECESSARY`
    See Also:
      - `FieldPosition`

  - ### formatToCharacterIterator

    public AttributedCharacterIterator formatToCharacterIterator(Object obj)
    Formats an Object producing an `AttributedCharacterIterator`. The returned `AttributedCharacterIterator` can be used 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. The prefix and the suffix parts of the returned iterator (if present) are represented by the attributes `NumberFormat.Field.PREFIX` and `NumberFormat.Field.SUFFIX` respectively.

    Overrides:
      `formatToCharacterIterator` in class `Format`
    Parameters:
      `obj` - The object to format
    Returns:
      an `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`

  - ### parse

    public Number parse(String text, ParsePosition pos)
    Parses text from the beginning of the given string to produce a `Number`.

    This method attempts to parse text starting at the index given by the `ParsePosition`. If parsing succeeds, then the index of the `ParsePosition` 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 `ParsePosition` can be used to indicate the starting point for the next call to this method. If an error occurs, then the index of the `ParsePosition` is not changed, the error index of the `ParsePosition` is set to the index of the character where the error occurred, and `null` is returned.

    This method will return a Long if possible (e.g., within the range [Long.MIN_VALUE, Long.MAX_VALUE] and with no decimals), otherwise a Double.

    The returned value is the numeric part in the given text multiplied by the numeric equivalent of the affix attached (For example, "K" = 1000 in `US locale`).

    A `CompactNumberFormat` can match the default prefix/suffix to a compact prefix/suffix interchangeably.

    Parsing can be done in either a strict or lenient manner, by default it is lenient.

    Parsing fails when lenient, if the prefix and/or suffix are non-empty and cannot be found due to parsing ending early, or the first character after the prefix cannot be parsed.

    Parsing fails when strict, if in `text`,

    - The default or a compact prefix is not found. For example, the `Locale.US` currency format prefix: "`$`"
    - The default or a compact suffix is not found. For example, a `Locale.US` `NumberFormat.Style.SHORT` compact suffix: "`K`"
    - `isGroupingUsed()` returns `false`, and the grouping symbol is found
    - `isGroupingUsed()` returns `true`, and `getGroupingSize()` is not adhered to
    - `isParseIntegerOnly()` returns `true`, and the decimal separator is found
    - `isGroupingUsed()` returns `true` and `isParseIntegerOnly()` returns `false`, and the grouping symbol occurs after the decimal separator
    - Any other characters are found, that are not the expected symbols, and are not digits that occur within the numerical portion

    The subclass returned depends on the value of `isParseBigDecimal()`.

    - If `isParseBigDecimal()` is false (the default), most integer values are returned as `Long` objects, no matter how they are written: `"17K"` and `"17.000K"` both parse to `Long.valueOf(17000)`. If the value cannot fit into `Long`, then the result is returned as `Double`. This includes values with a fractional part, infinite values, `NaN`, and the value -0.0.

      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 special cases negative and positive infinity and NaN are returned as `Double` instances holding the values of the corresponding `Double` constants.

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

    `CompactNumberFormat` parse does not allow parsing scientific notations. For example, parsing a string `"1.05E4K"` in `US locale` breaks at character 'E' and returns 1.05.

    Specified by:
      `parse` in class `NumberFormat`
    Parameters:
      `text` - the string to be parsed
      `pos` - a `ParsePosition` object with index and error index information as described above
    Returns:
      the parsed value, or `null` if the parse fails
    Throws:
      `NullPointerException` - if `text` or `pos` is null
    See Also:
      - `NumberFormat.isStrict()`

  - ### setMaximumIntegerDigits

    public void setMaximumIntegerDigits(int newValue)
    Sets the maximum number of digits allowed in the integer portion of a number. The maximum allowed integer range is 309, if the `newValue` > 309, then the maximum integer digits count is set to 309. Negative input values are replaced with 0.
    Overrides:
      `setMaximumIntegerDigits` in class `NumberFormat`
    Parameters:
      `newValue` - the maximum number of integer digits to be shown
    See Also:
      - `NumberFormat.getMaximumIntegerDigits()`

  - ### setMinimumIntegerDigits

    public void setMinimumIntegerDigits(int newValue)
    Sets the minimum number of digits allowed in the integer portion of a number. The maximum allowed integer range is 309, if the `newValue` > 309, then the minimum integer digits count is set to 309. Negative input values are replaced with 0.
    Overrides:
      `setMinimumIntegerDigits` in class `NumberFormat`
    Parameters:
      `newValue` - the minimum number of integer digits to be shown
    See Also:
      - `NumberFormat.getMinimumIntegerDigits()`

  - ### setMinimumFractionDigits

    public void setMinimumFractionDigits(int newValue)
    Sets the minimum number of digits allowed in the fraction portion of a number. The maximum allowed fraction range is 340, if the `newValue` > 340, then the minimum fraction digits count is set to 340. Negative input values are replaced with 0.
    Overrides:
      `setMinimumFractionDigits` in class `NumberFormat`
    Parameters:
      `newValue` - the minimum number of fraction digits to be shown
    See Also:
      - `NumberFormat.getMinimumFractionDigits()`

  - ### setMaximumFractionDigits

    public void setMaximumFractionDigits(int newValue)
    Sets the maximum number of digits allowed in the fraction portion of a number. The maximum allowed fraction range is 340, if the `newValue` > 340, then the maximum fraction digits count is set to 340. Negative input values are replaced with 0.
    Overrides:
      `setMaximumFractionDigits` in class `NumberFormat`
    Parameters:
      `newValue` - the maximum number of fraction digits to be shown
    See Also:
      - `NumberFormat.getMaximumFractionDigits()`

  - ### getRoundingMode

    public RoundingMode getRoundingMode()
    Gets the `RoundingMode` used in this `CompactNumberFormat`.
    Overrides:
      `getRoundingMode` in class `NumberFormat`
    Returns:
      the `RoundingMode` used for this `CompactNumberFormat`
    See Also:
      - `setRoundingMode(RoundingMode)`

  - ### setRoundingMode

    public void setRoundingMode(RoundingMode roundingMode)
    Sets the `RoundingMode` used in this `CompactNumberFormat`.
    Overrides:
      `setRoundingMode` in class `NumberFormat`
    Parameters:
      `roundingMode` - the `RoundingMode` to be used
    Throws:
      `NullPointerException` - if `roundingMode` is `null`
    See Also:
      - `getRoundingMode()`

  - ### getGroupingSize

    public int getGroupingSize()
    Returns the grouping size. Grouping size is the number of digits between grouping separators in the integer portion of a number. For example, in the compact number `"12,347 trillion"` for the `US locale`, the grouping size is 3.
    Returns:
      the grouping size
    See Also:
      - `setGroupingSize(int)`
      - `NumberFormat.isGroupingUsed()`
      - `DecimalFormatSymbols.getGroupingSeparator()`

  - ### setGroupingSize

    public void setGroupingSize(int newValue)
    Sets the grouping size. Grouping size is the number of digits between grouping separators in the integer portion of a number. For example, in the compact number `"12,347 trillion"` for the `US locale`, the grouping size is 3. The grouping size must be greater than or equal to zero and less than or equal to 127.
    Parameters:
      `newValue` - the new grouping size
    Throws:
      `IllegalArgumentException` - if `newValue` is negative or larger than 127
    See Also:
      - `getGroupingSize()`
      - `NumberFormat.setGroupingUsed(boolean)`
      - `DecimalFormatSymbols.setGroupingSeparator(char)`

  - ### isGroupingUsed

    public boolean isGroupingUsed()
    Returns true if grouping is used in this format. For example, with grouping on and grouping size set to 3, the number `12346567890987654` can be formatted as `"12,347 trillion"` in the `US locale`. The grouping separator is locale dependent.
    Overrides:
      `isGroupingUsed` in class `NumberFormat`
    Returns:
      `true` if grouping is used; `false` otherwise
    See Also:
      - `setGroupingUsed(boolean)`

  - ### setGroupingUsed

    public void setGroupingUsed(boolean newValue)
    Sets whether or not grouping will be used in this format.
    Overrides:
      `setGroupingUsed` in class `NumberFormat`
    Parameters:
      `newValue` - `true` if grouping is used; `false` otherwise
    See Also:
      - `isGroupingUsed()`

  - ### isParseIntegerOnly

    public boolean isParseIntegerOnly()
    Returns true if this format parses only an integer from the number component of a compact number. Parsing an integer means that only an integer is considered from the number component, prefix/suffix is still considered to compute the resulting output. For example, in the `US locale`, if this method returns `true`, the string `"1234.78 thousand"` would be parsed as the value `1234000` (1234 (integer part) * 1000 (thousand)) and the fractional part would be skipped. The exact format accepted by the parse operation is locale dependent.
    Overrides:
      `isParseIntegerOnly` in class `NumberFormat`
    Implementation Requirements:
      This implementation does not set the `ParsePosition` index to the position of the decimal symbol, but rather the end of the string.
    Returns:
      `true` if compact numbers should be parsed as integers only; `false` otherwise

  - ### setParseIntegerOnly

    public void setParseIntegerOnly(boolean value)
    Sets whether or not this format parses only an integer from the number component of a compact number.
    Overrides:
      `setParseIntegerOnly` in class `NumberFormat`
    Parameters:
      `value` - `true` if compact numbers should be parsed as integers only; `false` otherwise
    See Also:
      - `isParseIntegerOnly()`

  - ### isStrict

    public boolean isStrict()
    Returns `true` if this format will parse numbers strictly; `false` otherwise.
    Overrides:
      `isStrict` in class `NumberFormat`
    Returns:
      `true` if this format will parse numbers strictly; `false` otherwise
    Since:
      23
    See Also:
      - `setStrict(boolean)`
      - `parse(String, ParsePosition)`

  - ### setStrict

    public void setStrict(boolean strict)
    Change the leniency value for parsing. Parsing can either be strict or lenient, by default it is lenient.
    Overrides:
      `setStrict` in class `NumberFormat`
    Parameters:
      `strict` - `true` if parsing should be done strictly; `false` otherwise
    Since:
      23
    See Also:
      - `isStrict()`
      - `parse(String, ParsePosition)`

  - ### isParseBigDecimal

    public boolean isParseBigDecimal()
    Returns whether the `parse(String, ParsePosition)` method returns `BigDecimal`. The default value is false.
    Returns:
      `true` if the parse method returns BigDecimal; `false` otherwise
    See Also:
      - `setParseBigDecimal(boolean)`

  - ### setParseBigDecimal

    public void setParseBigDecimal(boolean newValue)
    Sets whether the `parse(String, ParsePosition)` method returns `BigDecimal`.
    Parameters:
      `newValue` - `true` if the parse method returns BigDecimal; `false` otherwise
    See Also:
      - `isParseBigDecimal()`

  - ### equals

    public boolean equals(Object obj)
    Compares the specified object with this `CompactNumberFormat` for equality. Returns true if the object is also a `CompactNumberFormat` and the two formats would format any value the same.
    Overrides:
      `equals` in class `NumberFormat`
    Implementation Requirements:
      This method performs an equality check with a notion of class identity based on `getClass()`, rather than `instanceof`. Therefore, in the equals methods in subclasses, no instance of this class should compare as equal to an instance of a subclass.
    Parameters:
      `obj` - the object to compare with
    Returns:
      true if this is equal to the other `CompactNumberFormat`
    See Also:
      - `Object.hashCode()`

  - ### hashCode

    public int hashCode()
    Returns the hash code for this `CompactNumberFormat`.
    Overrides:
      `hashCode` in class `NumberFormat`
    Implementation Requirements:
      Non-transient instance fields of this class are used to calculate a hash code value which adheres to the contract defined in `Objects.hashCode(java.lang.Object)`
    Returns:
      the hash code for this `CompactNumberFormat`
    See Also:
      - `Object.hashCode()`

  - ### toString

    public String toString()
    Returns a string identifying this `CompactNumberFormat`, for debugging.
    Overrides:
      `toString` in class `Object`
    Returns:
      a string identifying this `CompactNumberFormat`, for debugging

  - ### clone

    public CompactNumberFormat clone()
    Creates and returns a copy of this `CompactNumberFormat` instance.
    Overrides:
      `clone` in class `NumberFormat`
    Returns:
      a clone of this instance
    See Also:
      - `Cloneable`