Build a Library Manager - Step 18

JavaScript
1

Tell us what’s happening:

Kindly help me complete this project. I am unable to figure out the bug in my code:
this is the output instead of a single number:

Total number of pages for all library books:
0[object Object][object Object][object Object][object Object][object Object][object Object][object Object][object Object]
Navigated to Step 18
Found 2

Your code so far

const library = [
  {
    title: 'Your Next Five Moves: Master the Art of Business Strategy',
    author: 'Patrick Bet-David and Greg Dinkin',
    about: 'A book on how to plan ahead',
    pages: 320,
  },
  {
    title: 'Atomic Habits',
    author: 'James Clear',
    about: 'A practical book about discarding bad habits and building good ones',
    pages: 320,
  },
  {
    title: 'Choose Your Enemies Wisely: Business Planning for the Audacious Few',
    author: 'Patrick Bet-David',
    about:
      "A book that emphasizes the importance of identifying and understanding one's adversaries to succeed in the business world",
    pages: 304,
  },
  {
    title: 'The Embedded Entrepreneur',
    author: 'Arvid Kahl',
    about: 'A book focusing on how to build an audience-driven business',
    pages: 308,
  },
  {
    title: 'How to Be a Coffee Bean: 111 Life-Changing Ways to Create Positive Change',
    author: 'Jon Gordon',
    about: 'A book about effective ways to lead a coffee bean lifestyle',
    pages: 256,
  },
  {
    title: 'The Creative Mindset: Mastering the Six Skills That Empower Innovation',
    author: 'Jeff DeGraff and Staney DeGraff',
    about: 'A book on how to develop creativity and  innovation skills',
    pages: 168,
  },
  {
    title: 'Rich Dad Poor Dad',
    author: 'Robert Kiyosaki and Sharon Lechter',
    about: 'A book about financial literacy, financial independence, and building wealth. ',
    pages: 336,
  },
  {
    title: 'Zero to Sold',
    author: 'Arvid Kahl',
    about: 'A book on how to bootstrap a business',
    pages: 500,
  },
];

console.log("Books in the Library:\n");

function getBookInformation(catalog) {
  return catalog.map(book => `${book.title} by ${book.author}`).join("\n");
}

console.log(getBookInformation(library));

console.log("\nList of book summaries:\n");

function getBookSummaries(catalog) {
  return catalog.map((book) => book.about).join("\n");
}

console.log(getBookSummaries(library));

console.log("\nList of books by Arvid Kahl:\n");

function getBooksByAuthor(catalog, author) {
  return catalog.filter((book) => book.author === author);
}

console.log(getBooksByAuthor(library, "Arvid Kahl"));

console.log("\nList of books by James Clear:\n");
console.log(getBooksByAuthor(library, "James Clear"));

console.log("\nTotal number of pages for all library books:\n");


// User Editable Region

   function getTotalPages(pages) {
     const totalPages = pages.reduce((acc, curr) => acc + curr, 0);
    return totalPages;
   }
   console.log(getTotalPages(library));

// User Editable Region

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/138.0.0.0 Safari/537.36

Challenge Information:

Build a Library Manager - Step 18
https://www.freecodecamp.org/learn/full-stack-developer/workshop-library-manager/step-18

2

The ‘curr’ argument will give you the array itself. You need to get into the object within the array. I hope that helps.

1 Like
3

thank you for the hint. solved it!

4

Why is it that adding the optional parameter to initialize i.e “0”, the solution works and it no longer treats the output of acc + curr as a string? I think it’s somehow related to typing i.e it must be a number since the initial is a number. Is that correct?

5

if you do not give it an initial value, the initial value becomes the first value in the array, which in this case would be an object

1 Like