Fraction class final

An exact ratio of two integers: what division answers when a decimal cannot.

One divided by three is 1/3 here, and nothing is lost on the way. The ratio is always kept in lowest terms with a positive denominator, so equal ratios are equal objects.

final third = Decimal(1).divideToFraction(Decimal(3));
print(third);            // 1/3
print(third.round(4));   // 0.3333
print(third.toDouble()); // 0.3333333333333333

round and its three neighbours take a number of digits, and past a million they refuse it with DecimalDigitsOutOfRangeError: the power of ten such a request needs is a number nobody can hold.

Implemented types
Annotations
  • @immutable

Constructors

Fraction(BigInt dividend, BigInt divisor)
A ratio of dividend over divisor, reduced to lowest terms.
factory
Fraction.parse(String str)
Reads a ratio written as numerator/denominator, or a bare integer.
factory

Properties

denominator → BigInt
Denominator.
final
hashCode → int
The hash code for this object.
no setteroverride
inverse → Fraction
One divided by this fraction.
no setter
isNegative → bool
Whether this ratio is less than zero.
no setter
numerator → BigInt
Numerator.
final
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
sign → int
The sign: -1, 0 or 1.
no setter

Methods

abs() → Fraction
The absolute value of this fraction.
ceil([int fractionDigits = 0]) → Decimal
Rounds the fraction towards infinity to fractionDigits.
compareTo(Fraction other) → int
Compares this to other.
override
floor([int fractionDigits = 0]) → Decimal
Rounds the fraction towards negative infinity to fractionDigits.
noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
round([int fractionDigits = 0]) → Decimal
Rounds the fraction to the closest decimal with fractionDigits.
roundAwayFromZero([int fractionDigits = 0]) → Decimal
Rounds the fraction away from zero to fractionDigits.
roundToEven([int fractionDigits = 0]) → Decimal
Rounds the fraction to the closest decimal with fractionDigits, halves to even.
toDecimal() → Decimal
This ratio as a Decimal.
toDouble() → double
Converts this fraction to double.
toString() → String
A string representation of this object.
override
truncate([int fractionDigits = 0]) → Decimal
Rounds the fraction towards zero to fractionDigits.

Operators

operator *(Fraction other) → Fraction
Multiplies this fraction by other.
operator +(Fraction other) → Fraction
Adds other to this fraction.
operator -(Fraction other) → Fraction
Subtracts other from this fraction.
operator /(Fraction other) → Fraction
Divides this fraction by other.
operator ==(Object other) → bool
The equality operator.
override