Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

JavaScript JavaScript Array Iteration Methods Combining Array Methods Nested Data

Maksim Yin
Maksim Yin
3,673 Points

Why is it not iterable?

What did I do wrong? Thanks!

app.js
const customers = [
  {
    name: "Tyrone",
    personal: {
      age: 33,
      hobbies: ["Bicycling", "Camping"]
    }
  },
  {
    name: "Elizabeth",
    personal: {
      age: 25,
      hobbies: ["Guitar", "Reading", "Gardening"]
    }
  },
  {
    name: "Penny",
    personal: {
      age: 36,
      hobbies: ["Comics", "Chess", "Legos"]
    }
  }
];
let hobbies;

// hobbies should be: ["Bicycling", "Camping", "Guitar", "Reading", "Gardening", "Comics", "Chess", "Legos"]
// Write your code below

hobbies = customers
  .map(user => user.hobbies)
  .reduce((arr, favoriteHobbies) => [...arr, ...favoriteHobbies], [])

1 Answer

Steven Parker
Steven Parker
221,323 Points

The map method is not creating what you probably intended it for. That's because the customers objects do not have a hobbies property. They have a personal sub-object which has the hobbies.

Fixing that will pass the challenge. But for "extra credit" … you can also solve this using only reduce (with no map).