2018-09-30 23:01:58 +01:00
---
id: 587d7b89367417b2b2512b4a
title: Use Destructuring Assignment to Assign Variables from Nested Objects
challengeType: 1
2020-05-21 17:31:25 +02:00
isHidden: false
2019-08-05 09:17:33 -07:00
forumTopicId: 301214
2018-09-30 23:01:58 +01:00
---
## Description
< section id = 'description' >
2019-06-07 10:19:03 -05:00
You can use the same principles from the previous two lessons to destructure values from nested objects.
2019-06-20 09:28:53 -05:00
Using an object similar to previous examples:
2019-05-17 06:20:30 -07:00
```js
2019-06-07 10:19:03 -05:00
const user = {
johnDoe: {
age: 34,
email: 'johnDoe@freeCodeCamp .com'
}
2019-05-17 06:20:30 -07:00
};
```
2019-06-26 22:00:32 -05:00
Here's how to extract the values of object properties and assign them to variables with the same name:
2019-06-07 10:19:03 -05:00
```js
const { johnDoe: { age, email }} = user;
```
2019-06-26 22:00:32 -05:00
And here's how you can assign an object properties' values to variables with different names:
2019-06-07 10:19:03 -05:00
```js
const { johnDoe: { age: userAge, email: userEmail }} = user;
```
2018-09-30 23:01:58 +01:00
< / section >
## Instructions
< section id = 'instructions' >
2019-06-20 09:29:06 -05:00
Replace the two assignments with an equivalent destructuring assignment. It should still assign the variables < code > lowToday< / code > and < code > highToday< / code > the values of < code > today.low< / code > and < code > today.high< / code > from the < code > LOCAL_FORECAST< / code > object.
2018-09-30 23:01:58 +01:00
< / section >
## Tests
< section id = 'tests' >
```yml
2018-10-04 14:37:37 +01:00
tests:
2019-06-07 10:19:03 -05:00
- text: You should remove the ES5 assignment syntax.
testString: assert(!code.match(/lowToday = LOCAL_FORECAST\.today\.low/g) && !code.match(/highToday = LOCAL_FORECAST\.today.high/g))
- text: You should use destructuring to create the < code > lowToday</ code > variable.
2019-06-20 08:58:41 -05:00
testString: assert(code.match(/(var|const|let)\s*{\s*today\s*:\s*{\s*(low\s*:\s*lowToday[^}]*|[^,]*,\s*low\s*:\s*lowToday\s*)}\s*}\s*=\s*LOCAL_FORECAST(;|\s+|\/\/)/g));
2019-06-07 10:19:03 -05:00
- text: You should use destructuring to create the < code > highToday</ code > variable.
2019-06-20 08:58:41 -05:00
testString: assert(code.match(/(var|const|let)\s*{\s*today\s*:\s*{\s*(high\s*:\s*highToday[^}]*|[^,]*,\s*high\s*:\s*highToday\s*)}\s*}\s*=\s*LOCAL_FORECAST(;|\s+|\/\/)/g));
2020-03-08 07:46:28 -07:00
- text: < code > lowToday</ code > should be equal to < code > 64</ code > and < code > highToday</ code > should be equal to < code > 77</ code > .
testString: assert(lowToday === 64 & & highToday === 77);
2018-09-30 23:01:58 +01:00
```
< / section >
## Challenge Seed
< section id = 'challengeSeed' >
< div id = 'js-seed' >
```js
const LOCAL_FORECAST = {
2019-06-07 10:19:03 -05:00
yesterday: { low: 61, high: 75 },
today: { low: 64, high: 77 },
tomorrow: { low: 68, high: 80 }
2018-09-30 23:01:58 +01:00
};
2020-03-04 13:08:54 -06:00
// Only change code below this line
2019-06-07 10:19:03 -05:00
const lowToday = LOCAL_FORECAST.today.low;
const highToday = LOCAL_FORECAST.today.high;
2020-03-04 13:08:54 -06:00
// Only change code above this line
2018-09-30 23:01:58 +01:00
```
< / div >
< / section >
## Solution
< section id = 'solution' >
```js
2018-10-14 11:34:44 +05:30
const LOCAL_FORECAST = {
2019-06-07 10:19:03 -05:00
yesterday: { low: 61, high: 75 },
today: { low: 64, high: 77 },
tomorrow: { low: 68, high: 80 }
2018-10-14 11:34:44 +05:30
};
2020-03-08 07:46:28 -07:00
2019-06-08 15:46:28 -05:00
const { today: { low: lowToday, high: highToday }} = LOCAL_FORECAST;
2018-09-30 23:01:58 +01:00
```
2019-07-18 08:24:12 -07:00
2018-09-30 23:01:58 +01:00
< / section >