freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/es6/use-destructuring-assignment-to-assign-variables-from-nested-objects.english.md

id, title, challengeType

id	title	challengeType
587d7b89367417b2b2512b4a	Use Destructuring Assignment to Assign Variables from Nested Objects	1

Description

We can similarly destructure nested objects into variables. Consider the following code:

const a = {
  start: { x: 5, y: 6},
  end: { x: 6, y: -9 }
};
const { start : { x: startX, y: startY }} = a;
console.log(startX, startY); // 5, 6

In the example above, the variable start is assigned the value of a.start, which is also an object.

Instructions

Use destructuring assignment to obtain max of forecast.tomorrow and assign it to maxOfTomorrow.

Tests

tests:
  - text: <code>maxOfTomorrow</code> equals <code>84.6</code>
    testString: assert(getMaxOfTmrw(LOCAL_FORECAST) === 84.6, '<code>maxOfTomorrow</code> equals <code>84.6</code>');
  - text: nested destructuring was used
    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');

Challenge Seed

const LOCAL_FORECAST = {
  today: { min: 72, max: 83 },
  tomorrow: { min: 73.3, max: 84.6 }
};

function getMaxOfTmrw(forecast) {
  "use strict";
  // change code below this line
  const maxOfTomorrow = undefined; // change this line
  // change code above this line
  return maxOfTomorrow;
}

console.log(getMaxOfTmrw(LOCAL_FORECAST)); // should be 84.6

Solution

const LOCAL_FORECAST = {
  today: { min: 72, max: 83 },
  tomorrow: { min: 73.3, max: 84.6 }
};

function getMaxOfTmrw(forecast) {
  "use strict";
  // change code below this line
   const {tomorrow : {max : maxOfTomorrow}} = forecast; // change this line
  // change code above this line
  return maxOfTomorrow;
}

console.log(getMaxOfTmrw(LOCAL_FORECAST)); // should be 84.6