Still not getting the right array.

Question

I'm still not understanding how to return the array so each item is a string. Right now they are all one string. Will someone tell me how to fix my code so I can move on, please? How do I make hobbyArr an accumulator?
```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.reduce((hobbyArr, user) => [hobbyArr + user.personal.hobbies], []);
```

Rohald van Merode · Accepted Answer

Hey @Melissa Benton (https://teamtreehouse.com/melissabenton) 👋
Currently you're iterating over each of the customers and using the addition operator on the hobbies arrays. When using the addition operator (https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Addition_assignment) on arrays like that you'll end up with a string instead of an array of strings. 
This is basically what is happening in your current line of code: 
```js
hobbies = [] + ["Bicycling", "Camping"] + ["Guitar", "Reading", "Gardening"] + ["Comics", "Chess", "Legos"]
console.log(hobbies)
// "Bicycling,CampingGuitar,Reading,GardeningComics,Chess,Legos"
```
When you want to combine arrays with each other you'll want to be using the .concat method instead. This will make sure that the entries in each of the arrays will be combined into a single array: 
```js
hobbies = customers.reduce((acc, customer) => acc.concat(customer.personal.hobbies), []);
console.log(hobbies)
// ['Bicycling', 'Camping', 'Guitar', 'Reading', 'Gardening', 'Comics', 'Chess', 'Legos']
```
Alternatively you could use the spread operator to accomplish this: 
```js
hobbies = customers.reduce((acc, customer) => [...acc, ...customer.personal.hobbies], []);
console.log(hobbies)
// ['Bicycling', 'Camping', 'Guitar', 'Reading', 'Gardening', 'Comics', 'Chess', 'Legos']
```
Hope this helps 🙂

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Melissa Benton

Melissa Benton

Still not getting the right array.

1 Answer

Rohald van Merode

Rohald van Merode