sumOf

import { sumOf } from "jsr:@ende/collections";

function

function sumOf<T>(array: Iterable<T>, selector: (el: T, index: number) => number): number

Applies the given selector to all elements in the given collection and calculates the sum of the results.

array: Iterable<T>: The array to calculate the sum of.
selector: (el: T, index: number) => number: The selector function to get the value to sum. The function receives the element and its index.

Returns

The sum of all elements in the collection.

Example: Basic usage

import { sumOf } from "@ende/collections/sum-of";
import { assertEquals } from "@ende/assert";

const people = [
  { name: "Anna", age: 34 },
  { name: "Kim", age: 42 },
  { name: "John", age: 23 },
];

const totalAge = sumOf(people, (person) => person.age);

assertEquals(totalAge, 99);

Example: Using the index parameter

import { sumOf } from "@ende/collections/sum-of";
import { assertEquals } from "@ende/assert";

const array = [1, 2, 3];
const result = sumOf(array, (_, index) => index);

assertEquals(result, 3);

Source