Check for prop in collection

JavaScript
1

Tell us what’s happening:

How can I check whether my “tracks” given as argument in the function is present in the ‘collection’ obejct’s corresponding id.
As given in question: 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.
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!=""){
    value=prop;
    return collection;
  }
}

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

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

2

To access “tracks” value, you would do something like

collection[“2548”][“tracks”]. You could use either dot or bracket notations to access nested properties and values.

Then you could use if else statement to see if “tracks” property exists or not.

1 Like