JAVASCRIPT t Record Collection

Tell us what’s happening:

Your code so far

// Setup
var collection = {
    "2548": {
      "album": "Slippery When Wet",
      "artist": "Bon Jovi",
      "tracks": [ 
        "Let It Rock", 
        "You Give Love a Bad Name" 
    "2468": {
      "album": "1999",
      "artist": "Prince",
      "tracks": [ 
        "Little Red Corvette" 
    "1245": {
      "artist": "Robert Palmer",
      "tracks": [ ]
    "5439": {
      "album": "ABBA Gold"
// Keep a copy of the collection for tests
var collectionCopy = JSON.parse(JSON.stringify(collection));

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

   return collection;



// Alter values below to test your code
updateRecords(5439, "artist", "ABBA");

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/67.0.3396.87 Safari/537.36.

Link to the challenge:

// running test
After updateRecords(5439, “artist”, “ABBA”), artist should be “ABBA”
Cannot read property ‘tracks’ of undefined
After updateRecords(1245, “album”, “Riptide”), album should be “Riptide”
// tests completed

this is what i see when i run this.
what am i missing?
thanks in advance.

3 posts were merged into an existing topic: Javascript Record Collection

Please do not create duplicate topics for the same challenge question(s). I have put all your threads into the original one.