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---
id: a6e40f1041b06c996f7b2406
title: Finders Keepers
localeTitle: Buscadores guardianes
isRequired: true
challengeType: 5
---
## Description
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< 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.
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< / section >
## Instructions
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< section id = 'instructions' >
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## Tests
< section id = 'tests' >
```yml
tests:
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- text: ' < code > findElement([1, 3, 5, 8, 9, 10], function(num) { return num % 2 === 0; })</ code > debe devolver 8.'
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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.");'
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- text: ' < code > findElement([1, 3, 5, 9], function(num) { return num % 2 === 0; })</ code > debe devolver undefined.'
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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 >