es-toolkit/dist/compat/math/sumBy.d.mts

A state-of-the-art, high-performance JavaScript utility library with a small bundle size and strong type annotations.

/**
 * Computes the sum of the values that are returned by the `iteratee` function.
 *
 * It does not coerce values to `number`.
 *
 * @template T - The type of the array elements.
 * @param {ArrayLike<T> | null | undefined} array - The array to iterate over.
 * @param {((value: T) => number) | string} iteratee - The function invoked per iteration.
 * @returns {number} Returns the sum.
 *
 * @example
 * sumBy([1, undefined, 2], value => value); // => 3
 * sumBy(null); // => 0
 * sumBy(undefined); // => 0
 * sumBy([1, 2, 3]); // => 6
 * sumBy([1n, 2n, 3n]); // => 6n
 * sumBy([{ a: "1" }, { a: "2" }], object => object.a); // => "12"
 */
declare function sumBy<T>(array: ArrayLike<T> | null | undefined, iteratee?: ((value: T) => number) | string): number;

export { sumBy };