--description--
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:
const 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
.
Note: You will need to place a comma after every object in the array, unless it is the last object in the array.
--instructions--
Add a new album to the myMusic
array. Add artist
and title
strings, release_year
number, and a formats
array of strings.
--hints--
myMusic
should be an array
assert(Array.isArray(myMusic));
myMusic
should have at least two elements
assert(myMusic.length > 1);
The elements in the myMusic
array should be objects
myMusic.forEach(object => {assert.typeOf(object, 'object')})
Your object in myMusic
should have at least 4 properties
myMusic.forEach(object => {assert(Object.keys(object).length > 3); });
Your object in myMusic
should contain the property artist
which is a string
myMusic.forEach(object => {
assert.containsAllKeys(object, ['artist']);
assert.typeOf(object.artist, 'string')
})
Your object in myMusic
should contain the property title
which is a string
myMusic.forEach(object => {
assert.containsAllKeys(object, ['title']);
assert.typeOf(object.title, 'string')
})
Your object in myMusic
should contain the property release_year
which is a number
myMusic.forEach(object => {
assert.containsAllKeys(object, ['release_year']);
assert.typeOf(object.release_year, 'number')
})
Your object in myMusic
should contain a formats
property which is an array
myMusic.forEach(object => {
assert.containsAllKeys(object, ['formats']);
assert.typeOf(object.formats, 'array')
})
formats
should be an array of strings with at least two elements
myMusic.forEach(object => {
object.formats.forEach(format => {
assert.typeOf(format, 'string')
});
assert.isAtLeast(object.formats.length, 2)
})
--seed--
--after-user-code--
(function(x){ if (Array.isArray(x)) { return JSON.stringify(x); } return "myMusic is not an array"})(myMusic);
--seed-contents--
const myMusic = [
{
"artist": "Billy Joel",
"title": "Piano Man",
"release_year": 1973,
"formats": [
"CD",
"8T",
"LP"
],
"gold": true
}
];
--solutions--
const myMusic = [
{
"artist": "Billy Joel",
"title": "Piano Man",
"release_year": 1973,
"formats": [
"CS",
"8T",
"LP" ],
"gold": true
},
{
"artist": "ABBA",
"title": "Ring Ring",
"release_year": 1973,
"formats": [
"CS",
"8T",
"LP",
"CD",
]
}
];