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std/collections/sum_of.ts

Deno standard library
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// Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.// This module is browser compatible.
/** * Applies the given selector to all elements in the given collection and calculates the sum of the results * * Example: * * ```ts * import { sumOf } from "https://deno.land/std@$STD_VERSION/collections/mod.ts" * import { assertEquals } from "https://deno.land/std@$STD_VERSION/testing/asserts.ts" * * const people = [ * { name: 'Anna', age: 34 }, * { name: 'Kim', age: 42 }, * { name: 'John', age: 23 }, * ] * const totalAge = sumOf(people, i => i.age) * * assertEquals(totalAge, 99) * ``` */export function sumOf<T>( array: readonly T[], selector: (el: T) => number,): number { let sum = 0;
for (const i of array) { sum += selector(i); }
return sum;}