Question

Write a method deleteMsg that receives your messages, their total number and a message that you would like to remove. The method then searches for the message and delete it from your messages history. If the message was not found, an error message is reported. java

Answer 1

//Although a little more elaboration is needed to perfectly 
//understand the requirements, I tried my best to comprehend and implement.

package HomeworkLib1;
import java.util.ArrayList;
import java.util.Scanner;

public class Message {
        ArrayList<String> messages;
        Message(){
                messages = new ArrayList<String>();
                System.out.println("Message box created and set up.");
        }
        public static void main(String[] args) {
                Message m = new Message();                              //New Message box created
                m.messages.add("Hello there");          //Adding some messages to the message box
                m.messages.add("I am sme");
                m.messages.add("I work for HomeworkLib");
                m.messages.add("This is a java question");
                
                Scanner scan = new Scanner(System.in);
                String option="";
                boolean flag = false;
                
                do{
                        System.out.println("Do you want to delete a message? yes/no");
                        option = scan.nextLine();
                        if(option.contentEquals("yes")||option.contentEquals("no"))
                                flag = true;
                }while(!flag);
                if(option.contentEquals("yes")) {
                        System.out.println("Enter a message to search and delete: ");
                        
                        deleteMessage(m.messages);
                }

        }

        public static void deleteMessage(ArrayList<String> messages) {
                Scanner scan = new Scanner(System.in);
                String msg = scan.nextLine();
                boolean flag = false;
                for(int i=0; i<messages.size() ; i++) {
                        if(messages.get(i).contentEquals(msg)) {
                                flag = true;                    //Message found
                                messages.remove(i);             //Delete message
                        }
                }
                if(flag)
                        System.out.println("Message deleted.");
                else
                        System.out.println("Message not found.");
        }
}