recordCollection.js

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": [ 
        "1999", 
        "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" && value !== "") {
   if(collection[id][prop]) {
    collection[id][prop].push(value);
   }
   else {
    collection[id][prop]=[value];
   }
  } else if (value !== "") {
    collection[id][prop] = value;
  } else {
    delete collection[id][prop];
  }

  return collection;
}

// Alter values below to test your code

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

updateRecords(5439, "tracks", "Take a Chance on Me");

updateRecords(1245, "tracks", "Addicted to Love");

updateRecords(2468, "tracks", "Free");

updateRecords(2548, "tracks", "");

updateRecords(2548, "artist", "");

updateRecords(5439, "tracks", "Take a Chance on Me");

console.table(collection);