77 lines
1.9 KiB
Markdown
77 lines
1.9 KiB
Markdown
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---
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id: a6e40f1041b06c996f7b2406
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title: Finders Keepers
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localeTitle: Buscadores guardianes
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isRequired: true
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challengeType: 5
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---
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## Description
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<section id='description'>
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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.
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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>
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## Instructions
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<section id='instructions'>
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</section>
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## Tests
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<section id='tests'>
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```yml
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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.");'
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```
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</section>
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## Challenge Seed
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<section id='challengeSeed'>
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<div id='js-seed'>
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```js
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function findElement(arr, func) {
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let num = 0;
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return num;
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}
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findElement([1, 2, 3, 4], num => num % 2 === 0);
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```
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</div>
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</section>
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## Solution
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<section id='solution'>
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```js
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function findElement(arr, func) {
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let num;
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arr.some(e => {
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if (func(e)) {
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num = e;
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return true;
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}
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});
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return num;
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}
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findElement([1, 2, 3, 4], num => num % 2 === 0);
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```
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</section>
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