Javascript array inside another array

I am starting with the ionic framework and I am stuck in creating and calling an array inside another array.

I have the following code in my books.js :

.factory('Books', function() {

  // books data
  var books = [{
    id: 0,
    title: 'Sample Title',
    author: 'Sample Author',
    category: 'Horor, Fiction',
    cover: '/cover.jpeg',
    details: 'some details about the book',
    // my first attempt to create an array to store chapters info
    chapters: [
      {
        name: 'Chapter 1',
        filename: 'chapter1.html',
      },
      {
        name: 'Chapter 2',
        filename: 'Chapter2.html',
      }
    ]
  }, {
    id: 1,
    title: 'Sample Title Two',
    author: 'Sample Author two',
    category: 'Horor, Fiction',
    cover: '/cover.jpeg',
    details: 'some details about the book',
    // my first attempt to create an array to store chapters info
    chapters: [
      {

        name: 'Chapter 1',
        filename: 'chapter1.html',
      },
      {
        name: 'Chapter 2',
        filename: 'Chapter2.html',
      }
    ]
  },

when accessing data, I use {{book.title}} and it will output the title of the book. But I am not sure how to return the chapters values since each book has different numbers of chapters.

Perhaps assign a chapter ID for each chapter and call that ID ?