2018-09-30 23:01:58 +01:00
										 
									 
								 
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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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											2019-03-29 09:36:58 -07:00
										 
									 
								 
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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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											2019-02-21 14:00:21 +08:00
										 
									 
								 
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								In the example above, the variable <code>startX</code> is assigned the value of <code>a.start.x</code>.
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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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											2018-10-20 21:02:47 +03:00
										 
									 
								 
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								    testString: assert(getMaxOfTmrw(LOCAL_FORECAST) === 84.6, '<code>maxOfTomorrow</code> equals <code>84.6</code>');
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											2018-10-04 14:37:37 +01:00
										 
									 
								 
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								  - text: nested destructuring was used
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											2018-10-20 21:02:47 +03:00
										 
									 
								 
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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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											2018-09-30 23:01:58 +01:00
										 
									 
								 
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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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											2018-10-14 11:34:44 +05:30
										 
									 
								 
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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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