Can I repeat a section of code until I get a desired answer

so I've been learning java in my CS class at my high school, and I decided to remake a game that was my final project last year and add a bit more to it.

My problem is that I have the player input a number in order to make a specific choice, but if they input an invalid option, the code just ends, I've found a user with a similar problem here, but they are using if/else statements, and I'm using a switch statement

//shows the options the player can pick
    System.out.println("Start Game: 1");
    System.out.println("Close Game: 2");
    String choice = input.nextLine();

    switch(choice)
    {
        case "1": Variables.clear(); introduction(); break;
        case "2": System.exit(0);
        default: Variables.invalidAnswer();
    }

public static void introduction()
    {
        System.out.println("test");
    }

One of the answers was to try using a while(true) loop, which I tried

while(true)
{
    //shows the options the player can pick
    System.out.println("Start Game: 1");
    System.out.println("Close Game: 2");
    String choice = input.nextLine();

    switch(choice)
    {
        case "1": Variables.clear(); introduction(); break;
        case "2": System.exit(0);
        default: Variables.invalidAnswer(); Variables.clear();
    }
}

but when I do that, it just loops no matter what, I thought about adding another break statement after case "1", but I realized that wouldn't work. So I was wondering if there was a way to be able to make this work, or if there was a solution like this that works with a switch statement, any advice would be great, thanks.

Solution 1:

I'm always curious as to why people seem to forget that a do-while actually exists. Consider for a moment, the overall requirement - you must perform the loop at least once, so, we don't care about the exit condition until the end of the loop, for example...

String exitOption = "2";
String choice = null;
do {
    System.out.println("Start Game: 1");
    System.out.println("Close Game: 2");
    choice = input.nextLine();

    switch (choice) {
        case "1":
            Variables.clear();
            introduction();
            break;
        default:
            Variables.invalidAnswer();
    }
} while (!exitOption.equals(choice));

Here, I'm assuming you only ever want to exit the loop when the user selects 2, just beware of that

Flow control is a pretty basic concept of programming, you should take a closer look up:

• Control Flow Statements
• The while and do-while Statements

Solution 2:

Doing a break inside a switch-block will break the switch-block, not the while-loop. To break the outer while-loop, you can use a label:

import java.util.Scanner;

class Program {
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        inputLoop: while (true) {
            System.out.println("Start Game: 1");
            System.out.println("Close Game: 2");
            String choice = input.nextLine();
        
            switch(choice)
            {
                case "1": {
                    // Start the game
                    System.out.println("Game started");
                    break inputLoop;
                }
                case "2": {
                    // End the game
                    System.out.println("Game finished");
                    break inputLoop;
                }
                default: {
                    // Do nothing (the loop will be repeated)
                    System.out.println("Invalid answer");
                }
            }
        }
    }
}