Record Collection: How do you create an empty Array before adding the new value to the property?

Record Collection: How do you create an empty Array before adding the new value to the property?
0

#1

So I have most of the task ticked off except one. I’m stuck on this part

" If prop is "tracks" but the album doesn’t have a "tracks" property, create an empty array before adding the new value to the album’s corresponding property."

How do you create an empty Array then add it to the object? All the methods I have tried by myself doesn’t make sense soon I don’t know how should I go about creating an empty array then adding it to the object. Got any clues?


// 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": [ 
        "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 !== "") {
    collection[id][prop] = value;
  } else if (prop === "tracks" && collection[id].hasOwnProperty(prop) === false) {
    ???
    collection[id] = [prop];
  } else if (prop === "tracks" && value !== "") {
    collection[id][prop].push(value);
  } else if (value === "") {
    delete collection[id][prop];
  }
  
  return collection;
}

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

Link to the challenge:
https://learn.freecodecamp.org/javascript-algorithms-and-data-structures/basic-javascript/record-collection


#2

What have you tried? Surely you know how to create an empty array. As far as adding that array to an object, you will need to assign it to a specific property in the object. Show us what you have tried.


#3

I just completed it right after you mentioned assigned to a specific property in the object. Thank-you.