NumberFormatSI class

NumberFormatSI implements the International System of Units (SI) style conventions for displaying values of quantities. Specifically:

  • Three-digit groups of numbers with more than four digits are separated by spaces instead of commas (for example, 299 792 458, not 299,792,458) to avoid confusion with the decimal marker in European literature. This spacing is also used to the right of the decimal marker (for example, 12 345.678 90).
  • Uncertainty in the quantity's value may be optionally displayed... e.g., 1.234(11) or 1.234 +/- 0.011.

The value will be displayed in "computer scientific notation" (e.g., 1.3E9) if its exponent is less than -3 or greater than 6. These thresholds are arbitrary, but track with typical usage. If the exponent does not pass one of these thresholds then the number is simply displayed as a normal decimal number (e.g., 1 234.567 89).

The standard DecimalFormat class is unable to apply grouping to digits after the decimal. Therefore, this class directly extends NumberFormat and provides implementations for format and parse.

Implementers

Constructors

NumberFormatSI({bool unicode = false})
Constructs an instance.

Properties

currencyName String?
The name of the currency to print, in ISO 4217 form.
getter/setter pair
currencySymbol String
The symbol to be used when formatting this as currency.
no setter
decimalDigits int?
The number of decimal places to use when formatting.
no setter
hashCode int
The hash code for this object.
no setterinherited
locale String
Return the locale code in which we operate, e.g. 'en_US' or 'pt'.
no setter
localeZero int
The code point for the locale's zero digit.
no setter
maximumFractionDigits int
getter/setter pair
maximumIntegerDigits int
getter/setter pair
maximumSignificantDigits int?
getter/setter pair
minimumExponentDigits int
getter/setter pair
minimumFractionDigits int
getter/setter pair
minimumIntegerDigits int
getter/setter pair
minimumSignificantDigits int?
getter/setter pair
minimumSignificantDigitsStrict bool
Whether minimumSignificantDigits should cause trailing 0 in fraction part.
getter/setter pair
multiplier int
For percent and permille, what are we multiplying by in order to get the printed value, e.g. 100 for percent.
no setter
negativePrefix String
Variables to determine how number printing behaves.
no setter
negativeSuffix String
no setter
positivePrefix String
no setter
positiveSuffix String
no setter
runtimeType Type
A representation of the runtime type of the object.
no setterinherited
significantDigits int?
How many significant digits should we print.
getter/setter pair
significantDigitsInUse bool
getter/setter pair
symbols → NumberSymbols
Return the symbols which are used in our locale. Cache them to avoid repeated lookup.
no setter
unicode bool
Output in unicode (unicode thin spaces instead of regular ascii spaces).
getter/setter pair

Methods

adjustForExponent(String str) String
Subclasses should override if they wish to modify the number string to include an exponent and move the decimal point.
format(dynamic value) String
value is expected to be a Quantity, Number or num object.
insertSpaces(String str) String
Returns a String with spaces added according to SI guidelines.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
parse(String text) num
Parse the number represented by the string. If it's not parseable, throws a FormatException.
parseWith<R, P extends NumberParserBase<R>>(P parserGenerator(NumberFormat p1, String p2), String text) → R
Parse the number represented by the string using the parser created by the supplied parser generator. If it's not parseable, throws a FormatException.
simpleCurrencySymbol(String currencyCode) String
Returns the simple currency symbol for given currency code, or currencyCode if no simple symbol is listed.
toString() String
A string representation of this object.
inherited
tryParse(String text) num?
Parse the number represented by the string. If it's not parsable, returns null.
tryParseWith<R, P extends NumberParserBase<R>>(P parserGenerator(NumberFormat p1, String p2), String text) → R?
Parse the number represented by the string using the parser created by the supplied parser generator. If it's not parsable, returns null.
turnOffGrouping() → void
Explicitly turn off any grouping (e.g. by thousands) in this format.

Operators

operator ==(Object other) bool
The equality operator.
inherited

Static Methods

removeInsignificantZeros(String str) String
Removes any zeros at the end of a number string that follow a decimal point (except for one that immediately follows the decimal point).