Thread: Help with Snake Game Java Code: It's Impossible to Lose the Game

So the code I have I didn't make, but I want to mess around with it and make it better. I'm a beginner and just want to explore the language on my own, but I don't have any idea how to fix it. The game doesn't end when it hits the boundaries -- it keeps going on like a PacMan game. It also doesn't end when it collides with another section of itself. Can anyone tell me how to make this code work properly?

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.*;
 
class Snake extends JFrame implements KeyListener, Runnable {
 
    JPanel p1, p2;
    JButton[] lb = new JButton[200];
    JButton bonusfood;
    JTextArea t;
    int x = 500, y = 250, gu = 2, directionx = 1, directiony = 0, speed = 50, difference = 0, oldx, oldy, score = 0;
    int[] lbx = new int[300];
    int[] lby = new int[300];
    Point[] lbp = new Point[300];
    Point bfp = new Point();
    Thread myt;
    boolean food = false, runl = false, runr = true, runu = true, rund = true, bonusflag = true;
    Random r = new Random();
    JMenuBar mymbar;
    JMenu game, help, level;
 
    public void initializeValues() {
        gu = 3;
        lbx[0] = 100;
        lby[0] = 150;
        directionx = 10;
        directiony = 0;
        difference = 0;
        score = 0;
        food = false;
        runl = false;
        runr = true;
        runu = true;
        rund = true;
        bonusflag = true;
    }
 
    Snake() {
        super("Snake");
        setSize(500, 330);
        //Create Menue bar with functions
        creatbar();
        //initialize all variables
        initializeValues();
        // Start of UI design
        p1 = new JPanel();
        p2 = new JPanel();
        // t will view the score
        t = new JTextArea("Score ==>" + score);
        t.setEnabled(false);
        t.setBackground(Color.BLACK);
        // snake have to eat bonousfood to growup
        bonusfood = new JButton();
        bonusfood.setEnabled(false);
        // will make first snake
        createFirstSnake();
 
        p1.setLayout(null);
        p2.setLayout(new GridLayout(0, 1));
        p1.setBounds(0, 0, x, y);
        p1.setBackground(Color.blue);
        p2.setBounds(0, y, x, 30);
        p2.setBackground(Color.RED);
 
        p2.add(t); // will contain score board
        // end of UI design
        getContentPane().setLayout(null);
        getContentPane().add(p1);
        getContentPane().add(p2);
 
        show();
        setDefaultCloseOperation(EXIT_ON_CLOSE);
 
        addKeyListener(this);
        // start thread
        myt = new Thread(this);
        myt.start(); // go to run() method
    }
 
    public void createFirstSnake() {
        // Initially the snake has small length 3
        for (int i = 0; i < 3; i++) {
            lb[i] = new JButton("lb" + i);
            lb[i].setEnabled(false);
            p1.add(lb[i]);
            lb[i].setBounds(lbx[i], lby[i], 10, 10);
            lbx[i + 1] = lbx[i] - 10;
            lby[i + 1] = lby[i];
        }
    }
 
    public void creatbar() {
        mymbar = new JMenuBar();
 
        game = new JMenu("Game");
 
        JMenuItem newgame = new JMenuItem("New Game");
        JMenuItem exit = new JMenuItem("Exit");
 
        newgame.addActionListener(
                new ActionListener() {
 
                    public void actionPerformed(ActionEvent e) {
                        reset();
                    }
                });
 
        exit.addActionListener(new ActionListener() {
 
            public void actionPerformed(ActionEvent e) {
                System.exit(0);
            }
        });
 
        game.add(newgame);
        game.addSeparator();
        game.add(exit);
 
        mymbar.add(game);
 
        level = new JMenu("Level");
 
        mymbar.add(level);
 
        help = new JMenu("Help");
 
        JMenuItem creator = new JMenuItem("Creator");
        JMenuItem instruction = new JMenuItem("Instraction");
 
        creator.addActionListener(new ActionListener() {
 
            public void actionPerformed(ActionEvent e) {
                JOptionPane.showMessageDialog(p2, "Name :Abdullah al hasb\nRollno :2006331093\nSub :cse\ninstitute :sust");
            }
        });
 
        help.add(creator);
        help.add(instruction);
        mymbar.add(help);
 
        setJMenuBar(mymbar);
    }
 
    void reset() {
        initializeValues();
        p1.removeAll();
 
        myt.stop();
 
        createFirstSnake();
        t.setText("Score==>" + score);
 
        myt = new Thread(this);
        myt.start();
    }
 
    void growup() {
        lb[gu] = new JButton();
        lb[gu].setEnabled(false);
        p1.add(lb[gu]);
 
        int a = 10 + (10 * r.nextInt(48));
        int b = 10 + (10 * r.nextInt(23));
 
        lbx[gu] = a;
        lby[gu] = b;
        lb[gu].setBounds(a, b, 10, 10);
 
        gu++;
    }
    // this method contains the logic to move the snake. player will define the derection
    // this method just forward the snake to the right derection which deriction is pressed
    // by the player.
    void moveForward() {
        for (int i = 0; i < gu; i++) {
            lbp[i] = lb[i].getLocation();
        }
 
        lbx[0] += directionx;
        lby[0] += directiony;
        lb[0].setBounds(lbx[0], lby[0], 10, 10);
 
        for (int i = 1; i < gu; i++) {
            lb[i].setLocation(lbp[i - 1]);
        }
 
        if (lbx[0] == x) {
            lbx[0] = 10;
        } else if (lbx[0] == 0) {
            lbx[0] = x - 10;
        } else if (lby[0] == y) {
            lby[0] = 10;
        } else if (lby[0] == 0) {
            lby[0] = y - 10;
        }
 
        if (lbx[0] == lbx[gu - 1] && lby[0] == lby[gu - 1]) {
            food = false;
            score += 5;
            t.setText("Score==>" + score);
            if (score % 50 == 0 && bonusflag == true) {
                p1.add(bonusfood);
                bonusfood.setBounds((10 * r.nextInt(50)), (10 * r.nextInt(25)), 15, 15);
                bfp = bonusfood.getLocation();
                bonusflag = false;
            }
        }
 
        if (bonusflag == false) {
            if (bfp.x <= lbx[0] && bfp.y <= lby[0] && bfp.x + 10 >= lbx[0] && bfp.y + 10 >= lby[0]) {
                p1.remove(bonusfood);
                score += 100;
                t.setText("Score ==>" + score);
                bonusflag = true;
            }
        }
 
        if (food == false) {
            growup();
            food = true;
        } else {
            lb[gu - 1].setBounds(lbx[gu - 1], lby[gu - 1], 10, 10);
        }
 
        for (int i = 1; i < gu; i++) {
            if (lbp[0] == lbp[i]) {
                t.setText("GAME OVER " + score);
                try {
                    myt.join();
                } catch (InterruptedException ie) {
                }
                break;
            }
        }
 
        p1.repaint();
        show();
    }
 
    public void keyPressed(KeyEvent e) {
        // snake move to left when player pressed left arrow
        if (runl == true && e.getKeyCode() == 37) {
            directionx = -10; // means snake move right to left by 10pixels
            directiony = 0;
            runr = false;     // run right(runr) means snake cant move from left to right
            runu = true;      // run up   (runu) means snake can move from down to up
            rund = true;      // run down (run down) means snake can move from up to down
        }
        // snake move to up when player pressed up arrow
        if (runu == true && e.getKeyCode() == 38) {
            directionx = 0;
            directiony = -10; // means snake move from down to up by 10 pixel
            rund = false;     // run down (run down) means snake can move from up to down
            runr = true;      // run right(runr) means snake can move from left to right
            runl = true;      // run left (runl) means snake can move from right to left
        }
        // snake move to right when player pressed right arrow
        if (runr == true && e.getKeyCode() == 39) {
            directionx = +10; // means snake move from left to right by 10 pixel
            directiony = 0;
            runl = false;
            runu = true;
            rund = true;
        }
        // snake move to down when player pressed down arrow
        if (rund == true && e.getKeyCode() == 40) {
            directionx = 0;
            directiony = +10; // means snake move from left to right by 10 pixel
            runu = false;
            runr = true;
            runl = true;
        }
    }
 
    public void keyReleased(KeyEvent e) {
    }
 
    public void keyTyped(KeyEvent e) {
    }
 
    public void run() {
        for (;;) {
            // Move the snake move forword. In the start of the game snake move left to right,
            // if player press up, down, right or left arrow snake change its direction according to
            // pressed arrow
            moveForward();
            try {
                Thread.sleep(speed);
            } catch (InterruptedException ie) {
            }
        }
    }
}

Driver:

public class SnakeDriver {
 
 
    public static void main(String[] args) {
 
        new Snake();
    }
 
}

Could you give an example of where that might be useful? Also, I don't know if the code for the terminations boundaries has been written.

should I implement something like ActionListener and make a rectangle around the game board to be hit?

well what I was thinking was maybe set a rectangle with boundaries that, when hit, call the Action Listener to stop the game.

so how what would I use in that case?

sorry, exclude that "how"

what I want to do is create a boundary the size of the display window that when hit, ends the current game. I also need to find a way to the game to terminate when the snake body comes into contact with itself.

first i would recommend adding the method setResizable() right after the setSize() method in the constructor and make its parameter false so the user cant maximize the window becuase you've defined an explicit size for the game environment anyway... for your problem however u should make another method called endSnake() or some appropriate name that handles the case whenever the starting point of the snake touches a space that itself is already occupying and terminate because right now ur code just lets the snake overlap itself and continue playing

how would the game do that? he has hardcoded values i'm guessing because i ran the program and the game size didn't maximize with the window

so instead of hardcoding the x and y just declare them and pass them as the parameters for setBounds()? how will they know to resize with the window?

Hey I gotta solution if u needed it. Go to your moveForward() method and look at the for loop where "GAME OVER" is located... Change the lbp[0] == lbp[i] to lpb[0].equals(lbp[i]) and your game should work because lbp refers to objects and when comparing objects you should use the equals() method and only use == when comparing primitive data types like short, int & double... Hope it works!!!