Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

JavaScript JavaScript Array Iteration Methods Combining Array Methods Nested Data

Posted by Michael Sinoplis
Michael Sinoplis
2,424 Points

Seem to be missing something..

hobbies = customers .map(customer => customer.personal .map(hobbie => hobbie.hobbies)) .reduce((arr,hobbies) => [...arr,...hobbies],[]);

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(customer => customer.personal
       .map(hobbie => hobbie.hobbies))
  .reduce((arr,hobbies) => [...arr,...hobbies],[]);

1 Answer

Emmanuel C
Emmanuel C
10,636 Points
Emmanuel C
Emmanuel C
10,636 Points

You cant map the personal object, because map only works on arrays, nor do you need too. You can reach the hobbies array directly from the personal object with a dot. That'll return each hobbies array so you can use reduce on them and accumulate them. This is what i wrote for it to work 

hobbies = customers.map(customer => customer.personal.hobbies)
  .reduce((arr,hobbies) => [...arr,...hobbies],[]);