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JavaScript JavaScript Array Iteration Methods Combining Array Methods Nested Data

Joshua Igwe
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Joshua Igwe
Front End Web Development Techdegree Student 10,329 Points
Posted by Joshua Igwe
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Joshua Igwe
Front End Web Development Techdegree Student 10,329 Points

I am having an issue with this question. I am mapping over each object and selecting the hobby array.

I am having an issue with this question. I am mapping over each object and selecting the hobby array. After creating this array of arrays, I am using the reduce function as outlined in the lecture. I am getting an error saying my placeholder for the nested array is not iterable.

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(obj => obj).reduce((array, hobby) =>  [...array, ...hobby], []);

1 Answer

Blake Larson
Blake Larson
13,014 Points
Blake Larson
Blake Larson
13,014 Points

Close, but in the reduce function the hobby is not iterable because it's the customer object instead of the hobbies array inside of it. 

hobbies = customers.map(obj => obj.personal.hobbies).reduce((array, hobbies) =>  [...array, ...hobbies], []);

With just reduce

let hobbies = customers.reduce((array, person) => [...array, ...person.personal.hobbies], []);