如何在java中的while循环中设置switch语句

Question

I want to do a switch in while loop where at the break of every switch statement the while loop stops and ask for an input like F, R, C, Q. The statement below works but the statement does not break. Please help

public static void main(String[] args) throws IOException {

    // start both with 1 point
    int goodTotal = 50;
    int monTotal = 50;

    // input switch statement

    while (goodTotal > 0 && monTotal > 0) {

        System.out.print("Type a letter: ");
        System.out.println("\n");
        System.out.print("F: Go out and Fight ");
        System.out.println("\n");
        System.out.print("R: Rest ");
        System.out.println("\n");
        System.out.print("C: Check Stats ");
        System.out.println("\n");
        System.out.print("Q: Quit ");
        int input = System.in.read();

        System.out.println("You typed: " + (char) input);

        switch (input) {
        case 'f':
            System.out.println("Continue the game");
            break;
        case 'r':
            System.out.println("Players should rest");
            break;
        case 'c':
            System.out.println("Checking the status of the game");
            System.out.print("Goodman has " + goodTotal + " points and Monster has " + monTotal + " points");
            System.out.println("\n");
            break;
        case 'q':
            System.out.println("Game over");
            System.exit(input);
            break;
        default:
            System.out.println("Invalid selection");
            break;
        }

        // Set value of minimum and maximum damage
        int minDmg = 2;
        int maxDmg = 15;

        // Get random number;
        int damage = minDmg + Double.valueOf(Math.random() * (maxDmg - minDmg)).intValue();
        int damage2 = minDmg + Double.valueOf(Math.random() * (maxDmg - minDmg)).intValue();

        // remove value of damage from started value to get total value remaining
        goodTotal = goodTotal - damage;
        monTotal = monTotal - damage2;

        // print message if still in the game
        if (goodTotal > 0) {
            System.out.println("Goodman has " + goodTotal + " points left. Not bad, Man! ");
        }

        // if Goodman survives round 2 print a message of encouragement
        if (goodTotal > 0 && count > 1 && count <= 2) {
            System.out.print("This is encouraging. Goodman has lasted past roundhh " + count + ". ");

            // print new message if Goodman passes round 3
        } else if (goodTotal > 0 && count == 3) {
            System.out.print("Goodman is as strong as Samson. He has lasted round " + count
                    + " and still looks strong.");
            System.out.print(" 10 hit points has been added to your total");
        }

        if (monTotal > 0) {
            System.out.println("Wait, Monster has a total of " + monTotal + " points and is still in the game");
        }

        // exit if have less than 0 point, and print game over. Congratulate the winner
        if (goodTotal < 0) {
            System.out.println("Goodman you are out of the game");
            System.out.println("The monster will take over the village. This is sad");
            System.out.println("Game Over!");
        } else if (monTotal < 0) {
            System.out.println("Goodman has been victorious");
            System.out.println("The monster is dead. The people live!!!!");
            System.out.println("Game Over!");
        }
        System.out.println("This is the end of round " + count + " ");
        System.out.println("\n");
        count = count + 1;

    }

}

Answer 1

Use a label on the loop:

loop: while (goodTotal > 0 && monTotal > 0) {
    // ...
    switch (input) {
        case 'f':
            // ...
            break loop;
        case 'r':
            // ...
            break loop;
        // ...
    }
    // ...
}

Answer 2

You should use labelled break s.

Although it probably is better to rewrite the code in a way that doesn't need them, as they're not very easy to read.

Answer 3

input is of type int , but the case labels are character literals ( ie, f,r,c,q ). Why don't you just make the input also a char type ?

char input = System.in.read();