Simplify findLastIndex

This commit is contained in:
Siarhei
2018-05-14 16:51:56 +04:00
parent 2e122516cd
commit fe45b95fd0
2 changed files with 5 additions and 5 deletions

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@ -3,14 +3,14 @@
Returns the index of the last element for which the provided function returns a truthy value. Returns the index of the last element for which the provided function returns a truthy value.
Use `Array.map()` to map each element to an array with its index and value. Use `Array.map()` to map each element to an array with its index and value.
Use `Array.filter()` to remove elements for which `fn` returns falsey values, `Array.slice(-1)` to get the last one. Use `Array.filter()` to remove elements for which `fn` returns falsey values, `Array.pop()` to get the last one.
```js ```js
const findLastIndex = (arr, fn) => const findLastIndex = (arr, fn) =>
arr arr
.map((val, i) => [i, val]) .map((val, i) => [i, val])
.filter(val => fn(val[1], val[0], arr)) .filter(([i, val]) => fn(val, i, arr))
.slice(-1)[0][0]; .pop()[0];
``` ```
```js ```js

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@ -1,6 +1,6 @@
const findLastIndex = (arr, fn) => const findLastIndex = (arr, fn) =>
arr arr
.map((val, i) => [i, val]) .map((val, i) => [i, val])
.filter(val => fn(val[1], val[0], arr)) .filter(([i, val]) => fn(val, i, arr))
.slice(-1)[0][0]; .pop()[0];
module.exports = findLastIndex; module.exports = findLastIndex;