package project4;import javautilArrayList;import javautilScanner;public class MessageReceiver private static final int MAX_MESSAGES = 20; private ArrayListString messages; public MessageRece

The MessageReceiver class represents a message receiver system. It allows the user to perform various operations such as receiving messages, displaying messages, reading messages, deleting messages, and deleting all messages. The class uses an ArrayList to store the messages, with a maximum limit of 20 messages.

The main method of the class provides a menu-based interface for the user to interact with the message receiver system. The user can choose an option from the menu by entering the corresponding number. The program then performs the selected operation based on the user's choice.

Here is a breakdown of the methods in the MessageReceiver class:

1. receiveMessage(String message): This method is used to receive a new message. If the maximum limit of messages is reached, the oldest message is deleted before adding the new message to the ArrayList.

2. deleteOldestMessage(): This method deletes the oldest message from the ArrayList.

3. displayMessages(): This method displays all the messages in the ArrayList. If there are no messages, it displays a message indicating that there are no messages.

4. readMessage(int index): This method reads and displays a specific message from the ArrayList based on the given index. If the index is invalid, it displays an error message.

5. deleteMessage(int index): This method deletes a specific message from the ArrayList based on the given index. If the index is invalid, it displays an error message.

6. deleteAllMessages(): This method deletes all the messages from the ArrayList.

7. displayMenu(): This method displays the menu options for the user to choose from.

The main method creates an instance of the MessageReceiver class and starts a loop that continues until the user chooses to exit. Inside the loop, the program displays the menu, reads the user's choice, and performs the corresponding operation.

Overall, the MessageReceiver class provides a simple message receiver system that allows the user to manage received messages