freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-an.../es6/use-destructuring-assignmen...

2.3 KiB

id title challengeType forumTopicId dashedName
587d7b89367417b2b2512b49 Use Destructuring Assignment to Assign Variables from Objects 1 301215 use-destructuring-assignment-to-assign-variables-from-objects

--description--

Destructuring allows you to assign a new variable name when extracting values. You can do this by putting the new name after a colon when assigning the value.

Using the same object from the last example:

const user = { name: 'John Doe', age: 34 };

Here's how you can give new variable names in the assignment:

const { name: userName, age: userAge } = user;

You may read it as "get the value of user.name and assign it to a new variable named userName" and so on. The value of userName would be the string John Doe, and the value of userAge would be the number 34.

--instructions--

Replace the two assignments with an equivalent destructuring assignment. It should still assign the variables highToday and highTomorrow the values of today and tomorrow from the HIGH_TEMPERATURES object.

--hints--

You should remove the ES5 assignment syntax.

assert(
  !code.match(/highToday = HIGH_TEMPERATURES\.today/g) &&
    !code.match(/highTomorrow = HIGH_TEMPERATURES\.tomorrow/g)
);

You should use destructuring to create the highToday variable.

assert(
  code.match(
    /(var|const|let)\s*{\s*(today\s*:\s*highToday[^}]*|[^,]*,\s*today\s*:\s*highToday\s*)}\s*=\s*HIGH_TEMPERATURES(;|\s+|\/\/)/g
  )
);

You should use destructuring to create the highTomorrow variable.

assert(
  code.match(
    /(var|const|let)\s*{\s*(tomorrow\s*:\s*highTomorrow[^}]*|[^,]*,\s*tomorrow\s*:\s*highTomorrow\s*)}\s*=\s*HIGH_TEMPERATURES(;|\s+|\/\/)/g
  )
);

highToday should be equal to 77 and highTomorrow should be equal to 80.

assert(highToday === 77 && highTomorrow === 80);

--seed--

--seed-contents--

const HIGH_TEMPERATURES = {
  yesterday: 75,
  today: 77,
  tomorrow: 80
};

// Only change code below this line
  
const highToday = HIGH_TEMPERATURES.today;
const highTomorrow = HIGH_TEMPERATURES.tomorrow; 

// Only change code above this line

--solutions--

const HIGH_TEMPERATURES = {
  yesterday: 75,
  today: 77,
  tomorrow: 80
};

const { today: highToday, tomorrow: highTomorrow } = HIGH_TEMPERATURES;