--- id: 587d7b89367417b2b2512b49 title: Use Destructuring Assignment to Assign Variables from Objects challengeType: 1 --- ## Description
We saw earlier how spread operator can effectively spread, or unpack, the contents of the array. We can do something similar with objects as well. Destructuring assignment is special syntax for neatly assigning values taken directly from an object to variables. Consider the following ES5 code:
var voxel = {x: 3.6, y: 7.4, z: 6.54 };
var x = voxel.x; // x = 3.6
var y = voxel.y; // y = 7.4
var z = voxel.z; // z = 6.54
Here's the same assignment statement with ES6 destructuring syntax:
const { x, y, z } = voxel; // x = 3.6, y = 7.4, z = 6.54
If instead you want to store the values of voxel.x into a, voxel.y into b, and voxel.z into c, you have that freedom as well.
const { x : a, y : b, z : c } = voxel // a = 3.6, b = 7.4, c = 6.54
You may read it as "get the field x and copy the value into a," and so on.
## Instructions
Use destructuring to obtain the average temperature for tomorrow from the input object AVG_TEMPERATURES, and assign value with key tomorrow to tempOfTomorrow in line.
## Tests
```yml tests: - text: getTempOfTmrw(AVG_TEMPERATURES) should be 79 testString: 'assert(getTempOfTmrw(AVG_TEMPERATURES) === 79, "getTempOfTmrw(AVG_TEMPERATURES) should be 79");' - text: destructuring with reassignment was used testString: 'getUserInput => assert(getUserInput("index").match(/\{\s*tomorrow\s*:\s*tempOfTomorrow\s*}\s*=\s*avgTemperatures/g),"destructuring with reassignment was used");' ```
## Challenge Seed
```js const AVG_TEMPERATURES = { today: 77.5, tomorrow: 79 }; function getTempOfTmrw(avgTemperatures) { "use strict"; // change code below this line const tempOfTomorrow = undefined; // change this line // change code above this line return tempOfTomorrow; } console.log(getTempOfTmrw(AVG_TEMPERATURES)); // should be 79 ```
## Solution
```js const AVG_TEMPERATURES = { today: 77.5, tomorrow: 79 }; function getTempOfTmrw(avgTemperatures) { "use strict"; // change code below this line const {tomorrow:tempOfTomorrow} = avgTemperatures; // change this line // change code above this line return tempOfTomorrow; } console.log(getTempOfTmrw(AVG_TEMPERATURES)); // should be 79 ```