Problem statement

On a blog platform, authors frequently type redundant tags (like “coding”, “c#”, “coding”, “web”). To keep the UI clean and professional, the backend must instantly filter out these duplicates and return a perfectly alphabetized list of unique tags before saving them to the database.

Task requirements

• Create a TagProcessor class within a defined namespace.

• Implement a CleanTags(List<string> rawTags) method that accepts a list of messy, potentially duplicate tags.

• The method must remove all duplicate strings.

• The method must return a new list of these unique tags, sorted alphabetically.

• Test the implementation by passing a list with duplicates and printing the cleaned, sorted result using a foreach loop.

Constraints

• Use a HashSet<string> to perform the duplicate filtering efficiently.

• Initialize the HashSet<string> by passing the raw list directly into its constructor to immediately strip duplicates.

• Convert the unique set back into a List<string> so it can be sorted.

• Use the Sort() method on the resulting list before returning it.

Good luck trying the exercise! If you’re unsure how to proceed, check the “Solution” tab above.

Get hints

• The HashSet<T> constructor can accept an existing collection. Passing the list directly into the constructor via new(rawTags) is the fastest way to strip duplicates without writing a loop.

• To convert the set back to a list, you can use the List<T> constructor similarly: new(myHashSet).

• The Sort() method modifies the list in place and does not return a value. Call it on your list on a separate line before returning the list variable.