Record Collection: Do I understand the data structure?

Hi,
Collection is a JSON object, containing an array of keys that correspond to an array of keys containing strings or another arrays?

object{
id= [100,200,300,]
100=[albumTitle, artist, tracks]
100.tracks=[name1,name2,name3]
};
If I would like to print the album title of 100 inside our JSON object “collection”, I would type console.log(collection[100].albumTitle); which takes the keyed item from array element 100, which is contained inside ourJSON object.

I’d appreciate someone putting this in their own English to explain a little better whats inside this JSON object.
Your code so far


// Setup
var collection = {
2548: {
  albumTitle: 'Slippery When Wet',
  artist: 'Bon Jovi',
  tracks: ['Let It Rock', 'You Give Love a Bad Name']
},
2468: {
  albumTitle: '1999',
  artist: 'Prince',
  tracks: ['1999', 'Little Red Corvette']
},
1245: {
  artist: 'Robert Palmer',
  tracks: []
},
5439: {
  albumTitle: 'ABBA Gold'
}
};

// Only change code below this line
function updateRecords(object, id, prop, value) {
if (prop !== 'tracks' && value !== "") {
  object[id][prop] = value;
} else if (prop === "tracks" && !object[id].hasOwnProperty("tracks")) {
  object[id][prop] = [value];
} else if (prop === "tracks" && value !== "") {
  object[id][prop].push(value);
} else if (value === "") {
  delete object[id][prop];
}
return object;
}

updateRecords(collection, 5439, 'artist', 'ABBA');
console.log();

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Challenge: Record Collection

Link to the challenge:

This is a fantastic question.

Here it is in my words:
You have a data collection object which holds information about records. This information is accessed by id.

const collection = {
  id: // Info about a record,
};

The information about each record (again, accessed from the parent object by id), is stored in objects of the form

const record = {
  albumTitle: // String with name of record,
  artist: // String with name of artist,
  tracks: // Array with strings holding names of tracks
};

Are there parts I can explain better?

What is id? It seems to act like a key.

yeah, id is the key that you use to access each record.

var collection = {
  2548: { /* Data for record 2548 */ },
  2468: { /* Data for record 2468 */ },
  1245: { /* Data for record 1245 */ },
  5439: { /* Data for record 5439 */ },
};

I’m reading about Javascript objects on W3 school I should have gone there first! I believe each id is a nested object within the object collection! The properties of artist, tracks, albumTitle are key/value pairs within id, which itself is a property of the ‘collection’ object?

Bingo! That’s exactly what’s going on here - nested objects

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Great thanks :smile:

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