Store evey calculation as item in Array

Question

I have made a console calculator that the user input the numbers and the operation in one line like this;

5 + 5

after pressing enter it will show the result like this;

Result: 5 + 5 = 10

I am trying to store every complete result to an array so I can print or list them when the user pressed (L) but I could not succeed as my code always stores the last calculation. I want the calculations printed when the user press L like this:

Operation: L
Previous Calculations:
5 + 5 = 100
4 * 5 = 20

Here is my code and I thank you in advance.

public static void main(String[] args) {
        do {
            System.out.print("**********************************************\n"
                    + "Enter L to list previous calculations.\nEnter Q to exit.\n"
                    + "**********************************************\n"
                    + "Operation: ");

            Scanner scan = new Scanner(System.in);
            String input = scan.nextLine();
            String[] operation = input.split(" ");

            if (input.length() < 5) {
                if (input.equals("q")) {
                    System.out.print("\n\n**********************************************\n"
                            + "ByeBye\n"
                            + "**********************************************\n");
                    System.exit(0);
                }
                if (input.equals("l")) {
                    System.out.println("\n\nPrevious Calculations:\n");
                    continue;
                } else {
                    System.out.println("\n\nWrong Operation!!!");
                    continue;

                }
            }

            int first_number = Integer.parseInt(operation[0]);
            int second_number = Integer.parseInt(operation[2]);

            int outcome = 0;

            boolean wrong_operation = false;
            String operator = operation[1];

            switch (operator) {
                case "+":
                    outcome = first_number + second_number;
                    break;
                case "-":
                    outcome = first_number - second_number;
                    break;
                case "*":
                    outcome = first_number * second_number;
                    break;
                case "/":
                    outcome = first_number / second_number;
                    break;
                default:
                    wrong_operation = true;

            }

            String answer;
            String array_item;

            if (wrong_operation) {
                System.out.println("\n\nWrong Operation!!! " + "(" + operator + ")");
            } else {
                answer = String.valueOf(outcome);
                array_item = input + " = " + answer;
                System.out.println("\n\nResult: " + array_item);
                char[] myArray = array_item.toCharArray();
                System.out.println(myArray);
            }

        } while (true);

    }

Answer 1

You can declare a list to store the previous calculations before de do declaration, like this:

    public static void main(String[] args) {
        List<String> previousCalculations = new ArrayList<>(); // Declare list
        do {
            System.out.print("**********************************************\n"
                    + "Enter L to list previous calculations.\nEnter Q to exit.\n"
                    + "**********************************************\n"
                    + "Operation: ");
        ...
        ...

Then store the results after you show the answer

                answer = String.valueOf(outcome);
                array_item = input + " = " + answer;
                System.out.println("\n\nResult: " + array_item);

                previousCalculations.add(array_item); // Store results

And finally print the previous calculations when the option is selected:

                if (input.equals("l")) {
                    System.out.println("\n\nPrevious Calculations:");

                    // Print the previous calculations
                    for(String calc : previousCalculations) {
                        System.out.println(calc);
                    }
                    continue;
                } else {
                    System.out.println("\n\nWrong Operation!!!");
                    continue;

                }