89 lines
2.6 KiB
Markdown
89 lines
2.6 KiB
Markdown
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---
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id: 587d7dae367417b2b2512b7b
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title: Understand Own Properties
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localeTitle: Entender propiedades propias
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challengeType: 1
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---
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## Description
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<section id='description'>
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En el siguiente ejemplo, el constructor de <code>Bird</code> define dos propiedades: <code>name</code> y <code>numLegs</code> :
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<blockquote>function Bird(name) {<br> this.name = name;<br> this.numLegs = 2;<br>}<br><br>let duck = new Bird("Donald");<br>let canary = new Bird("Tweety");</blockquote>
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<code>name</code> y <code>numLegs</code> se denominan propiedades <code>own</code> , porque se definen directamente en el objeto de instancia. Eso significa que el <code>duck</code> y el <code>canary</code> tienen su propia copia separada de estas propiedades.
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De hecho, cada instancia de <code>Bird</code> tendrá su propia copia de estas propiedades.
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El siguiente código agrega todas las propiedades <code>own</code> de <code>duck</code> a la matriz <code>ownProps</code> :
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<blockquote>let ownProps = [];<br><br>for (let property in duck) {<br> if(duck.hasOwnProperty(property)) {<br> ownProps.push(property);<br> }<br>}<br><br>console.log(ownProps); // prints [ "name", "numLegs" ]</blockquote>
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</section>
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## Instructions
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<section id='instructions'>
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Agrega las propiedades <code>own</code> de <code>canary</code> a la matriz <code>ownProps</code> .
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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>ownProps</code> debe incluir los valores <code>"numLegs"</code> y <code>"name"</code> .
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testString: 'assert(ownProps.indexOf("name") !== -1 && ownProps.indexOf("numLegs") !== -1, "<code>ownProps</code> should include the values <code>"numLegs"</code> and <code>"name"</code>.");'
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- text: Resuelva este desafío sin usar el método <code>Object.keys()</code> .
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testString: 'assert(!/\Object.keys/.test(code), "Solve this challenge without using the built in method <code>Object.keys()</code>.");'
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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 Bird(name) {
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this.name = name;
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this.numLegs = 2;
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}
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let canary = new Bird("Tweety");
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let ownProps = [];
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// Add your code below this line
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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 Bird(name) {
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this.name = name;
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this.numLegs = 2;
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}
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let canary = new Bird("Tweety");
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function getOwnProps (obj) {
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const props = [];
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for (let prop in obj) {
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if (obj.hasOwnProperty(prop)) {
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props.push(prop);
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}
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}
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return props;
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}
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const ownProps = getOwnProps(canary);
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```
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</section>
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