Record Collection doubt

JavaScript
1

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": [ 
        "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(collection.id.prop !== "tracks" && prop=="tracks" )
  {collection.id[prop]=[];
  collection.id.prop.push(value);
  }
  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");

Your browser information:

User Agent is: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36.

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

2

Well, first thing to note – please indicate the behavior you’re having a problem with in the ‘tell us what’s happening:’ bit when you ask for help.

That said, I copied and pasted your code, and the message is all about ‘cannot set property of undefined’. Which makes sense: collection.id is NOT the same as collection[id].

The id is a parameter passed in, thus it needs to be referenced in bracket notation rather than dot notation. You tend to interchange between them willy-nilly. If you are using a variable to define a value, for example id='4334', prop='artist';, those must be in brackets. If you simply collection.id then you’re looking for a property named id on that collection. By using collection[id] you’re saying (using the above values) `collection[‘4334’].

Try that and you’ll get a whole NEW set of errors to learn from!

1 Like