Destructuring Objects

2.1

Destructure the first book object from the books array into variables called title, author and ISBN.

const {title, author, ISBN} = books[0];

2.2

Each book object has the keywords property. Destructure the first book object from the books array into a variable called tags. The tags variable should be assigned with the value of the keywords property.

const {keywords: tags} = books[0];

2.3

The seventh book from the books array is missing the programmingLanguage property. Destructure the seventh book object (books[6]) into variables called language and programmingLanguage. Assign the programmingLanguage variable with a default value of 'unknown'.

const {language, programmingLanguage = 'unknown'} = books[6];

2.4

Below are two variables called bookTitle and bookAuthor. Reassign them with the values of the title and author properties of the first book object from the books array.

let bookTitle = 'unknown';
let bookAuthor = 'unknown';

({title: bookTitle, author: bookAuthor} = books[0]);

2.5

Each book object has a deeply nested rating property as illustrated below:

  {
    title: 'Algorithms',
    ...
    thirdParty: {
      goodreads: {
        rating: 4.41,              // <-- HERE
        ratingsCount: 1733,
        reviewsCount: 63,
        fiveStarRatingCount: 976,
        oneStarRatingCount: 13
      }
    }
  },

Destructure the first book object from the books array into a variable called bookRating. In the result of your destructuring, the bookRating variable should be assigned with the value of the book[0].thirdParty.goodreads.rating property.

Please do most of the work on the left side of the assignment operator: const ... = books[0];

const {thirdParty: {goodreads: {rating: bookRating}}} = books[0];

2.6

Write a function called printBookInfo that has three parameters called title, author and year. This function should work for a single object passed as an argument, and it should log to the console information about the book in this format: "${title} by ${author}, ${year}".

If year is undefined (was not passed), it should be assigned with a default value of 'year unknown'.

Code:

printBookInfo({ title: 'Algorithms', author: 'Robert Sedgewick', year: '2011' });

Expected output:

"Algorithms by Robert Sedgewick, 2011"

Code (missing year):

printBookInfo({ title: 'Algorithms', author: 'Robert Sedgewick' });

Expected output:

"Algorithms by Robert Sedgewick, year unknown"

function printBookInfo({title, author, year = 'year unknown'}) { console.log(`${title} by ${author}, ${year}`); }