Sometimes you may want to store data in a flexible Data Structure. A JavaScript object is one way to handle flexible data. They allow for arbitrary combinations of strings, numbers, booleans, arrays, functions, and objects. Here's an example of a complex data structure:

var ourMusic = [
  {
    "artist": "Daft Punk",
    "title": "Homework",
    "release_year": 1997,
    "formats": [
      "CD",
      "Cassette",
      "LP"
    ],
    "gold": true
  }
];

This is an array which contains one object inside. The object has various pieces of metadata about an album. It also has a nested "formats" array. If you want to add more album records, you can do this by adding records to the top level array. Objects hold data in a property, which has a key-value format. In the example above, "artist": "Daft Punk" is a property that has a key of "artist" and a value of "Daft Punk". JavaScript Object Notation or JSON is a related data interchange format used to store data.

{
  "artist": "Daft Punk",
  "title": "Homework",
  "release_year": 1997,
  "formats": [
    "CD",
    "Cassette",
    "LP"
  ],
  "gold": true
}

Note
You will need to place a comma after every object in the array, unless it is the last object in the array.

```yml tests: - text: myMusic should be an array testString: 'assert(Array.isArray(myMusic), "myMusic should be an array");' - text: myMusic should have at least two elements testString: 'assert(myMusic.length > 1, "myMusic should have at least two elements");' - text: 'myMusic[1] should be an object' testString: 'assert(typeof myMusic[1] === "object", "myMusic[1] should be an object");' - text: 'myMusic[1] should have at least 4 properties' testString: 'assert(Object.keys(myMusic[1]).length > 3, "myMusic[1] should have at least 4 properties");' - text: 'myMusic[1] should contain an artist property which is a string' testString: 'assert(myMusic[1].hasOwnProperty("artist") && typeof myMusic[1].artist === "string", "myMusic[1] should contain an artist property which is a string");' - text: 'myMusic[1] should contain a title property which is a string' testString: 'assert(myMusic[1].hasOwnProperty("title") && typeof myMusic[1].title === "string", "myMusic[1] should contain a title property which is a string");' - text: 'myMusic[1] should contain a release_year property which is a number' testString: 'assert(myMusic[1].hasOwnProperty("release_year") && typeof myMusic[1].release_year === "number", "myMusic[1] should contain a release_year property which is a number");' - text: 'myMusic[1] should contain a formats property which is an array' testString: 'assert(myMusic[1].hasOwnProperty("formats") && Array.isArray(myMusic[1].formats), "myMusic[1] should contain a formats property which is an array");' - text: formats should be an array of strings with at least two elements testString: 'assert(myMusic[1].formats.every(function(item) { return (typeof item === "string")}) && myMusic[1].formats.length > 1, "formats should be an array of strings with at least two elements");' ```