freeCodeCamp/curriculum/challenges/spanish/02-javascript-algorithms-an.../basic-algorithm-scripting/finders-keepers.spanish.md

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2018-10-08 17:34:43 +00:00
---
id: a6e40f1041b06c996f7b2406
title: Finders Keepers
localeTitle: Buscadores guardianes
isRequired: true
challengeType: 5
---
## Description
<section id='description'>
Cree una función que examine una matriz (primer argumento) y devuelva el primer elemento de la matriz que pase una prueba de verdad (segundo argumento). Si ningún elemento pasa la prueba, devuelva indefinido.
Recuerda usar <a href='http://forum.freecodecamp.org/t/how-to-get-help-when-you-are-stuck/19514' target='_blank'>Read-Search-Ask</a> si te atascas. Trate de emparejar el programa. Escribe tu propio código.
</section>
## Instructions
<section id='instructions'>
</section>
## Tests
<section id='tests'>
```yml
tests:
- text: &#39; <code>findElement([1, 3, 5, 8, 9, 10], function(num) { return num % 2 === 0; })</code> debe devolver 8.&#39;
testString: 'assert.strictEqual(findElement([1, 3, 5, 8, 9, 10], function(num) { return num % 2 === 0; }), 8, "<code>findElement([1, 3, 5, 8, 9, 10], function(num) { return num % 2 === 0; })</code> should return 8.");'
- text: &#39; <code>findElement([1, 3, 5, 9], function(num) { return num % 2 === 0; })</code> debe devolver undefined.&#39;
testString: 'assert.strictEqual(findElement([1, 3, 5, 9], function(num) { return num % 2 === 0; }), undefined, "<code>findElement([1, 3, 5, 9], function(num) { return num % 2 === 0; })</code> should return undefined.");'
```
</section>
## Challenge Seed
<section id='challengeSeed'>
<div id='js-seed'>
```js
function findElement(arr, func) {
let num = 0;
return num;
}
findElement([1, 2, 3, 4], num => num % 2 === 0);
```
</div>
</section>
## Solution
<section id='solution'>
```js
function findElement(arr, func) {
let num;
arr.some(e => {
if (func(e)) {
num = e;
return true;
}
});
return num;
}
findElement([1, 2, 3, 4], num => num % 2 === 0);
```
</section>