Mappings Exercise

Create a contract that adheres to the following specifications.

Contract

Create a single contract called FavoriteRecords. It should not inherit from any other contracts. It should have the following properties:

State Variables

The contract should have the following state variables. It is up to you to decide if any supporting variables are useful.

• A public mapping approvedRecords, which returns true if an album name has been added as described below, and false if it has not
• A mapping called userFavorites that indexes user addresses to a mapping of string record names which returns true or false, depending if the user has marked that album as a favorite

Loading Approved Albums

Using the method of your choice, load approvedRecords with the following:

• Thriller
• Back in Black
• The Bodyguard
• The Dark Side of the Moon
• Their Greatest Hits (1971-1975)
• Hotel California
• Come On Over
• Rumours
• Saturday Night Fever

Get Approved Records

Add a function called getApprovedRecords. This function should return a list of all of the names currently indexed in approvedRecords.

Add Record to Favorites

Create a function called addRecord that accepts an album name as a parameter. If the album is on the approved list, add it to the list under the address of the sender. Otherwise, reject it with a custom error of NotApproved with the submitted name as an argument.

Users' Lists

Write a function called getUserFavorites that retrieves the list of favorites for a provided address memory.

Reset My Favorites

Add a function called resetUserFavorites that resets userFavorites for the sender.

Submit your Contract and Earn an NFT Badge! (BETA)