Welcome! Today, we will explore creating a simple address book application using JavaScript Map. This task will help you understand manipulating Map in JavaScript, focusing on adding, retrieving, and deleting entries. By the end of this lesson, you'll have a solid grasp of these fundamental operations.

In this task, we will implement three methods to manage our address book:

• addContact(name, phoneNumber): Adds a new contact. Returns false if the contact already exists; otherwise, it adds the contact and returns true. In this task, let's assume phone numbers do not change, so it's not allowed to overwrite the existing contact's number.
• getContact(name): Retrieves the phone number for a given name. Returns undefined if the contact does not exist.
• deleteContact(name): Deletes a contact with the given name. Returns true if the contact exists and is deleted, otherwise.