65 lines
1.8 KiB
Markdown
65 lines
1.8 KiB
Markdown
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---
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id: 587d7b89367417b2b2512b4a
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title: Use Destructuring Assignment to Assign Variables from Nested Objects
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challengeType: 1
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videoUrl: ''
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localeTitle: 使用解构分配从嵌套对象分配变量
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---
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## Description
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<section id="description">我们可以类似地将<em>嵌套</em>对象解构为变量。请考虑以下代码： <blockquote> const a = { <br>开始：{x：5，y：6}， <br>结束：{x：6，y：-9} <br> }; <br> const {start：{x：startX，y：startY}} = a; <br> console.log（startX，startY）; // 5,6 </blockquote>在上面的示例中，变量<code>start</code>被赋予<code>a.start</code>的值，该值也是一个对象。 </section>
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## Instructions
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<section id="instructions">用解构赋值来获得<code>max</code>的<code>forecast.tomorrow</code>并将其分配给<code>maxOfTomorrow</code> 。 </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>maxOfTomorrow</code>等于<code>84.6</code>
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testString: 'assert(getMaxOfTmrw(LOCAL_FORECAST) === 84.6, "<code>maxOfTomorrow</code> equals <code>84.6</code>");'
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- text: 使用嵌套解构
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testString: 'getUserInput => assert(getUserInput("index").match(/\{\s*tomorrow\s*:\s*\{\s*max\s*:\s*maxOfTomorrow\s*\}\s*\}\s*=\s*forecast/g),"nested destructuring was used");'
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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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const LOCAL_FORECAST = {
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today: { min: 72, max: 83 },
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tomorrow: { min: 73.3, max: 84.6 }
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};
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function getMaxOfTmrw(forecast) {
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"use strict";
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// change code below this line
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const maxOfTomorrow = undefined; // change this line
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// change code above this line
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return maxOfTomorrow;
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}
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console.log(getMaxOfTmrw(LOCAL_FORECAST)); // should be 84.6
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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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// solution required
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```
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</section>
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