Lesson Review Record Collection

Author

Created by Rafase282

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Details

You are given a JSON object representing (a small part of) your record collection. Each album is identified by a unique id number and has several properties. Not all albums have complete information.

Instructions

Write a function which takes an id, a property (prop), and a value.

For the given id in collection:

If value is non-blank (value !== ""), then update or set the value for the prop.

If the prop is "tracks" and value is non-blank, push the value onto the end of the tracks array.

If value is blank, delete that prop.

Always return the entire collection object.

Remember to use Read-Search-Ask if you get stuck. Try to pair program. Write your own code.

Useful Links

• Waypoint: Accessing Objects Properties with Bracket Notation
• Waypoint: Add New Properties to a JavaScript Object
• Waypoint: Delete Properties from a JavaScript Object
• [Waypoint: Accessing Nested Objects in JSON] (http://www.freecodecamp.com/challenges/waypoint-accessing-nested-objects-in-json)

Problem Explanation:

• Change the code below // Only change code below this line and up to // Alter values below to test your code

• Take note that you are editing the inside of the update function

• For the given id parameter, which is associated to the collection object:

  • If the value parameter isn't an empty string, update (or set) the value parameter for the prop parameter
  • If the prop parameter is equal to "tracks" and the value isn't an empty string, push the value onto the end of the tracks array
  • If value is an empty string, delete that prop from the object

• Finally, return the collection object

Hint: 1

• Use an else if statement to check the needed steps.

Hint: 2

• The second step listed in the instructions should be first in your else if statement.

Hint: 3

• To access the value of a key in this object, you will use collection[id][prop]

Spoiler Alert!

Solution ahead!

Code Solution:

// 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 update(id, prop, value) {
  if (value === '') {
    delete collection[id][prop];
  } else if (prop !== 'tracks') {
    collection[id][prop] = value;
  } else {
    collection[id][prop].push(value);
  }


  return collection;
}

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

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