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								---
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								id: 587d7b8a367417b2b2512b4d
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								title: Use Destructuring Assignment to Pass an Object as a Function's Parameters
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								challengeType: 1
							 
						 
					
						
							
								
									
										
										
										
											2019-08-05 09:17:33 -07:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								forumTopicId: 301217
							 
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								---
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								## Description
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								< section  id = 'description' >  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								In some cases, you can destructure the object in a function argument itself.
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								Consider the code below:
							 
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								const profileUpdate = (profileData) => {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  const { name, age, nationality, location } = profileData;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  // do something with these variables
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								This effectively destructures the object sent into the function. This can also be done in-place:
							 
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								const profileUpdate = ({ name, age, nationality, location }) => {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  /* do something with these fields */
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								This removes some extra lines and makes our code look neat.
							 
						 
					
						
							
								
									
										
										
										
											2019-08-20 09:36:22 -04:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								This has the added benefit of not having to manipulate an entire object in a function — only the fields that are needed are copied inside the function.
							 
						 
					
						
							
								
									
										
										
										
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								< / section >  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								## Instructions
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								< section  id = 'instructions' >  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								Use destructuring assignment within the argument to the function < code > half< / code >  to send only < code > max< / code >  and < code > min< / code >  inside the function.
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								< / section >  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								## Tests
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								< section  id = 'tests' >  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```yml
							 
						 
					
						
							
								
									
										
										
										
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								tests:
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  -  text: < code > stats</ code >  should be an < code > object</ code > .
							 
						 
					
						
							
								
									
										
										
										
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								    testString: assert(typeof stats === 'object');
							 
						 
					
						
							
								
									
										
										
										
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								  -  text: < code > half(stats)</ code >  should be < code > 28.015</ code > 
							 
						 
					
						
							
								
									
										
										
										
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								    testString: assert(half(stats) === 28.015);
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  -  text: Destructuring should be used.
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    testString: assert(code.replace(/\s/g, '').match(/half=\({\w+,\w+}\)/));
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  -  text: Destructured parameter should be used.
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    testString: assert(!code.match(/stats\.max|stats\.min/));
							 
						 
					
						
							
								
									
										
										
										
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								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								< / section >  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								## Challenge Seed
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								< section  id = 'challengeSeed' >  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								< div  id = 'js-seed' >  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								const stats = {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  max: 56.78,
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  standard_deviation: 4.34,
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  median: 34.54,
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  mode: 23.87,
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  min: -0.75,
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  average: 35.85
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								};
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								// change code below this line
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								const half = (stats) => (stats.max + stats.min) / 2.0; // use function argument destructuring
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								// change code above this line
							 
						 
					
						
							
								
									
										
										
										
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								console.log(stats); // should be object
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								console.log(half(stats)); // should be 28.015
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								< / div >  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								< / section >  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								## Solution
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								< section  id = 'solution' >  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```js
							 
						 
					
						
							
								
									
										
										
										
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								const stats = {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  max: 56.78,
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  standard_deviation: 4.34,
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  median: 34.54,
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  mode: 23.87,
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  min: -0.75,
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  average: 35.85
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								};
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								const half = ( {max, min} ) => (max + min) / 2.0;
							 
						 
					
						
							
								
									
										
										
										
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								```
							 
						 
					
						
							
								
									
										
										
										
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								< / section >