Where does the records and id come from?

Tell us what’s happening:
Describe your issue in detail here.
Anybody can tell me where the records and id from?
In my opinion, records and id is not defined in the recordCollection Object, so I can’t understand records[id][prop], even though I knew the answer following is right, but I’m really confused about where the records and id come from, and how they’re connected with recordCollection object, thanks!

  **Your code so far**

// Setup
const recordCollection = {
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(records, id, prop, value) {
if (prop !== 'tracks' && value !== "") {
  records[id][prop] = value;
} else if (prop === "tracks" && records[id].hasOwnProperty("tracks") === false) {
  records[id][prop] = [value];
} else if (prop === "tracks" && value !== "") {
} else if (value === "") {
  delete records[id][prop];
return records;

updateRecords(recordCollection, 5439, 'artist', 'ABBA');
  **Your browser information:**

User Agent is: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.4844.84 Safari/537.36

Challenge: Record Collection

Link to the challenge:

they are funcion parameters, their values are defined when the function is called


Thanks so much, I was really confused about this.

This topic was automatically closed 182 days after the last reply. New replies are no longer allowed.