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79d9012432
* fix(curriculum): tests quotes * fix(curriculum): fill seed-teardown * fix(curriculum): fix tests and remove unneeded seed-teardown
82 lines
2.1 KiB
Markdown
82 lines
2.1 KiB
Markdown
---
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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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---
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## Description
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<section id='description'>
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We can similarly destructure <em>nested</em> objects into variables.
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Consider the following code:
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<blockquote>const a = {<br> start: { x: 5, y: 6},<br> end: { x: 6, y: -9 }<br>};<br>const { start : { x: startX, y: startY }} = a;<br>console.log(startX, startY); // 5, 6</blockquote>
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In the example above, the variable <code>start</code> is assigned the value of <code>a.start</code>, which is also an object.
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</section>
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## Instructions
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<section id='instructions'>
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Use destructuring assignment to obtain <code>max</code> of <code>forecast.tomorrow</code> and assign it to <code>maxOfTomorrow</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>maxOfTomorrow</code> equals <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: nested destructuring was used
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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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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 {tomorrow : {max : maxOfTomorrow}} = forecast; // 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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</section>
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