Usage

sum([1, 2, 3]); // => 6

sum([{ value: 1 }, { value: 2 }, { value: 3 }], (item) => item.value); // => 6

sum([true, false, true], (item) => (item ? 1 : 0)); // => 2

Installation

CLI

npx atmx add helper sum

Manually

Copy and paste the following method into @/utils/helpers/sum.ts:

/**
* Add up numbers related to an array in 1 of 2 ways:
*
* 1. Sum all numbers in an array of numbers
* 2. Sum all numbers returned by a callback function that maps
*    each item in an array to a number.
*
* @example
* sum([1, 2, 3]) // => 6
*
* sum([
*   {value: 1},
*   {value: 2},
*   {value: 3}
* ], (item) => item.value) // => 6
*
* sum([true, false, true], (item) => item ? 1 : 0) // => 2
*/
export function sum(array: readonly number[]): number;
export function sum<T>(array: readonly T[], fn: (item: T) => number): number;
export function sum<T>(
array: readonly any[],
fn?: (item: T) => number,
): number {
return (array || []).reduce((acc, item) => acc + (fn ? fn(item) : item), 0);
}