Project 5: Contact Book

Build a Contact Book

Combine File I/O, String methods, and Generics to build a simple in-memory contact book that adds, looks up, and lists contacts.

YOUR TASK

Create a program that:

Uses a HashMap<String, String> to store name → phone number pairs
Adds: Alice → 555-1234, Bob → 555-5678, Carol → 555-9999
Looks up and prints Bob's number
Prints all contacts sorted alphabetically by name

Need a hint?

Use TreeMap instead of HashMap to automatically sort by key.

Or sort: new ArrayList<>(map.keySet()).sort(...)

Lookup: System.out.println("Bob: " + contacts.get("Bob"));

Expected Output:

Bob: 555-5678
--- All Contacts ---
Alice: 555-1234
Bob: 555-5678
Carol: 555-9999

Language:

Input:

Code Editor Ready

Output

Console

Console initialized...
Ready for Project 5: Contact Book

> Try using TreeMap for automatic alphabetical sorting
> Contacts must appear in A → Z order to pass!