Fraction

The Fraction class provides precise fractional arithmetic using BigInt numerator and denominator.

Import

import { Fraction } from '@uniswap/sdk-core-next'

Constructor

new Fraction(numerator: BigintIsh, denominator?: BigintIsh)

Parameters

Name	Type	Default	Description
`numerator`	`BigintIsh`	-	The numerator
`denominator`	`BigintIsh`	`1n`	The denominator

BigintIsh can be bigint, string, or number.

Example

import { Fraction } from '@uniswap/sdk-core-next'
 
// Create fractions
const half = new Fraction(1, 2)
const quarter = new Fraction(1n, 4n)
const fromString = new Fraction('100', '3')
 
// Arithmetic
const sum = half.add(quarter)       // 3/4
const diff = half.subtract(quarter) // 1/4
const product = half.multiply(2)    // 1
const quotient = half.divide(2)     // 1/4
 
// Formatting
half.toSignificant(2)  // "0.5"
half.toFixed(4)        // "0.5000"

Properties

`numerator`

readonly numerator: bigint

`denominator`

readonly denominator: bigint

`quotient`

get quotient(): bigint

Returns the floor division result (numerator / denominator).

const f = new Fraction(7, 3)
f.quotient // 2n

`remainder`

get remainder(): Fraction

Returns the remainder after floor division.

const f = new Fraction(7, 3)
f.remainder // Fraction(1, 3)

`asFraction`

get asFraction(): Fraction

Returns a new Fraction with the same numerator/denominator. Useful for converting subclasses back to Fraction.

Methods

`invert()`

invert(): Fraction

Returns a new fraction with numerator and denominator swapped.

new Fraction(3, 4).invert() // Fraction(4, 3)

`add(other)`

add(other: Fraction | BigintIsh): Fraction

Returns a new fraction that is the sum of this and the other.

new Fraction(1, 4).add(new Fraction(1, 4)) // Fraction(2, 4) = 1/2
new Fraction(1, 2).add(1)                  // Fraction(3, 2)

`subtract(other)`

subtract(other: Fraction | BigintIsh): Fraction

Returns a new fraction that is this minus the other.

new Fraction(3, 4).subtract(new Fraction(1, 4)) // Fraction(2, 4) = 1/2

`multiply(other)`

multiply(other: Fraction | BigintIsh): Fraction

Returns a new fraction that is the product.

new Fraction(1, 2).multiply(new Fraction(2, 3)) // Fraction(2, 6) = 1/3
new Fraction(1, 2).multiply(4)                  // Fraction(4, 2) = 2

`divide(other)`

divide(other: Fraction | BigintIsh): Fraction

Returns a new fraction that is the quotient.

new Fraction(1, 2).divide(new Fraction(3, 4)) // Fraction(4, 6) = 2/3
new Fraction(1, 2).divide(2)                  // Fraction(1, 4)

`lessThan(other)`

lessThan(other: Fraction | BigintIsh): boolean

new Fraction(1, 4).lessThan(new Fraction(1, 2)) // true

`equalTo(other)`

equalTo(other: Fraction | BigintIsh): boolean

new Fraction(1, 2).equalTo(new Fraction(2, 4)) // true

`greaterThan(other)`

greaterThan(other: Fraction | BigintIsh): boolean

new Fraction(3, 4).greaterThan(new Fraction(1, 2)) // true

`toSignificant(significantDigits, format?, rounding?)`

toSignificant(
  significantDigits: number,
  format?: { groupSeparator?: string },
  rounding?: Rounding
): string

Returns a string with the specified number of significant digits.

import { Rounding } from '@uniswap/sdk-core-next'
 
const f = new Fraction(1, 3)
f.toSignificant(4)                                    // "0.3333"
f.toSignificant(2)                                    // "0.33"
f.toSignificant(4, { groupSeparator: ',' })           // "0.3333"
f.toSignificant(4, {}, Rounding.ROUND_UP)             // "0.3334"

`toFixed(decimalPlaces, format?, rounding?)`

toFixed(
  decimalPlaces: number,
  format?: { groupSeparator?: string },
  rounding?: Rounding
): string

Returns a string with the specified number of decimal places.

const f = new Fraction(1, 3)
f.toFixed(4)                                          // "0.3333"
f.toFixed(2)                                          // "0.33"
f.toFixed(4, { groupSeparator: ',' }, Rounding.ROUND_UP) // "0.3334"

Rounding Modes

import { Rounding } from '@uniswap/sdk-core-next'
 
Rounding.ROUND_DOWN    // 0 - Truncate
Rounding.ROUND_HALF_UP // 1 - Round half away from zero (default)
Rounding.ROUND_UP      // 2 - Always round away from zero