JSPlayground created by saifsultanc - https://repl.it/@saifsultanc/JSPlayground

main.js

// 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 (value.length == 0) {
    delete collection[id][prop];
  }
  else {
    collection[id][prop] = value;
  }
  return collection;
}

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


// practice code
/*console.log("Hello World");
var number = 5; // in-line comment
console.log(++number);
number = "five";
console.log(number);
var a;
console.log(a);
a = a + "lol";
console.log(a);

var product = 2.01 * 2.5;
console.log(product);

var str = "Hello";
console.log(str);
str[0]='h';
console.log(str);

var myArray = [5, 6, 7];
console.log(myArray.pop());
myArray.push(8);
console.log(myArray);
console.log(myArray.shift());
myArray.unshift(4);
console.log(JSON.stringify(myArray));


var a = 3;
var b = "3";
if (a=b)
  console.log("test 1 true");
else
  console.log("test 1 false");

if (a==b)
  console.log("test 2 true");
else
  console.log("test 2 false");

if (a===b)
  console.log("test 3 true");
else
  console.log("test 3 false");


var student = {
  "name" : "John",
  "marks" : 67
};
student["age"] = 12;
delete student["age"];
console.log(student);
*/