TypeError: Cannot set properties of undefined (setting 'prop')

Tell us what’s happening:
Describe your issue in detail here.

I tried to use dot notation instead of bracket notation to access and update the nested object here but I keep on receiving the Type Error about prop being undefined

  **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 === '') {
  delete records.id.prop;
} else if (prop === 'tracks') {
  records.id.prop = records.id.prop.push(value);
} else {
  records.id.prop = 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/97.0.4692.99 Safari/537.36

Challenge: Record Collection

Link to the challenge:

You cannot use dot notation with variables that hold property names… That just not how dot notation works.

Appreciate the feedback; I watched a few more videos on notation to better grasp the idea. I’ve always thought dot and bracket notation can be used interchangeably, but now I know better haha

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