es-toolkit/dist/array/flatMap.js

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

const require_flatten = require("./flatten.js");
//#region src/array/flatMap.ts
/**
* Maps each element in the array using the iteratee function and flattens the result up to the specified depth.
*
* @template T - The type of elements within the array.
* @template U - The type of elements within the returned array from the iteratee function.
* @template D - The depth to which the array should be flattened.
* @param arr - The array to flatten.
* @param iteratee - The function that produces the new array elements. It receives the element, its index, and the array.
* @param depth - The depth level specifying how deep a nested array structure should be flattened. Defaults to 1.
* @returns The new array with the mapped and flattened elements.
*
* @example
* const arr = [1, 2, 3];
*
* flatMap(arr, (item: number) => [item, item]);
* // [1, 1, 2, 2, 3, 3]
*
* flatMap(arr, (item: number) => [[item, item]], 2);
* // [1, 1, 2, 2, 3, 3]
*/
function flatMap(arr, iteratee, depth = 1) {
	return require_flatten.flatten(arr.map((item, index) => iteratee(item, index, arr)), depth);
}
//#endregion
exports.flatMap = flatMap;