Basic JavaScript - Record Collection

Tell us what’s happening:
Hi, thanks for lending me a hand.

Although I have already passed the test, I am still confused why my code didn’t pass before I slightly changed my code from to records[id][prop].

When I used the dot notation, my code doesn’t work at all, but when I changed them to the bracket notation, my code suddenly worked. Is that any difference between the two kinds of notation that I didn’t notice?

Thanks again. Have a good day.

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(value == ""){
  } else if (prop != "tracks"){ = value
  } else if (records[id].hasOwnProperty("tracks")){[prop].push(value);
  } else {["tracks"] = [];[prop].push(value);
  return records;

updateRecords(recordCollection, 5439, "artist", "ABBA")

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/ Safari/537.36 Edg/105.0.1343.33

Challenge: Basic JavaScript - Record Collection

Link to the challenge:


Dot notation can only be used with the exact, literal property name. prop isn’t the literal property name; it is a variable holding the property name. For variables holding property names, bracket notation is mandatory.

It’s a common mix up that takes a few times to remember.

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I will take that in mind.
Thank you very much !!!

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