percentage-change

Binary operator of percentage-change

Install

npm install percentage-change

Use

▸ percentageChange(start: number, end: number): Option‹number›

Binary operator of percentage-change

Parameters:

| Name | Type | | ------- | ------ | | start | number | | end | number |

Returns: Option‹number›

import { percentageChange } from "percentage-change";
import { some, none } from "fp-ts/Option";

/* Standard use */
percentageChange(100, 200);
//=>some(100)

percentageChange(100, 75);
//=>some(-25)

/* Special cases */
percentageChange(0, 0);
//=>some(0)

percentageChange(0, 100);
//=>some(Infinity)

percentageChange(100, 0);
//=>some(-100)

percentageChange(NaN, 0);
//=>none

percentageChange(0, NaN);
//=>none

percentageChange(Infinity, 0); // -Infinity works the same way
//=>none

percentageChange(0, Infinity); // -Infinity works the same way
//=>none

Option type compliant with the fantasy-land specification.