@monstermann/fn/dist/array/lastIndexOfOrElse.js

A utility library for TypeScript.

import { dfdlT } from "@monstermann/dfdl";

//#region src/array/lastIndexOfOrElse.ts
/**
* `lastIndexOfOrElse(target, value, orElse)`
*
* Returns the index of the last occurrence of `value` in `target`. If `value` is not found, calls `orElse` with the original array.
*
* ```ts
* lastIndexOfOrElse([1, 2, 3, 2], 2, () => -1); // 3
* lastIndexOfOrElse([1, 2, 3], 4, (arr) => arr.length); // 3
* ```
*
* ```ts
* pipe(
*     [1, 2, 3, 2],
*     lastIndexOfOrElse(2, () => -1),
* ); // 3
* pipe(
*     [1, 2, 3],
*     lastIndexOfOrElse(4, (arr) => arr.length),
* ); // 3
* ```
*/
const lastIndexOfOrElse = dfdlT((target, value, orElse) => {
	const idx = target.lastIndexOf(value);
	return idx < 0 ? orElse(target) : idx;
}, 3);

//#endregion
export { lastIndexOfOrElse };