Here’s a simple shoot-’em-up game in Java that you can run on OnlineGDB. Since OnlineGDB supports text-based Java programs and does not have graphical support, the game will be console-based.<\/p>\n
The player controls a spaceship (^) that can move left and right while shooting (|) at incoming enemies (X). The game ends when an enemy reaches the bottom:<\/p>\n
The game is displayed on a 10×20 grid.
\nThe player can move left (a) and right (d) and shoot (w).
\nEnemies (X) fall from the top.
\nThe game ends when an enemy reaches the bottom or the player shoots all enemies.<\/p>\n
import java.util.Scanner;
\nimport java.util.Random;<\/p>\n
public class Main {
\nstatic final int WIDTH = 20;
\nstatic final int HEIGHT = 10;
\nstatic char[][] grid = new char[HEIGHT][WIDTH];
\nstatic int playerX = WIDTH \/ 2;
\nstatic int bulletY = -1;
\nstatic int bulletX = -1;
\nstatic int enemyX;
\nstatic int enemyY = 0;
\nstatic boolean gameOver = false;<\/p>\n
public static void main(String[] args) {
\nScanner scanner = new Scanner(System.in);
\nRandom random = new Random();
\nenemyX = random.nextInt(WIDTH);<\/p>\n
while (!gameOver) {
\nupdateGrid();
\nprintGrid();
\nSystem.out.print(“Move (a\/d) or Shoot (w): “);
\nchar move = scanner.next().charAt(0);
\nhandleInput(move);
\nmoveEnemy();
\ncheckCollision();
\n}<\/p>\n
System.out.println(“Game Over!”);
\n}<\/p>\n
static void updateGrid() {
\nfor (int i = 0; i < HEIGHT; i++)
\nfor (int j = 0; j < WIDTH; j++)
\ngrid[i][j] = ‘ ‘;<\/p>\n
if (bulletY >= 0) grid[bulletY][bulletX] = ‘|’;
\ngrid[enemyY][enemyX] = ‘X’;
\ngrid[HEIGHT – 1][playerX] = ‘^’;
\n}<\/p>\n
static void printGrid() {
\nfor (char[] row : grid) {
\nfor (char cell : row) System.out.print(cell);
\nSystem.out.println();
\n}
\n}<\/p>\n
static void handleInput(char move) {
\nif (move == ‘a’ && playerX > 0) playerX–;
\nif (move == ‘d’ && playerX < WIDTH – 1) playerX++;
\nif (move == ‘w’ && bulletY == -1) {
\nbulletX = playerX;
\nbulletY = HEIGHT – 2;
\n}
\nmoveBullet();
\n}<\/p>\n
static void moveBullet() {
\nif (bulletY >= 0) bulletY–;
\nif (bulletY < 0) bulletX = -1;
\n}<\/p>\n
static void moveEnemy() {
\nenemyY++;
\nif (enemyY >= HEIGHT – 1) gameOver = true;
\n}<\/p>\n
static void checkCollision() {
\nif (bulletY == enemyY && bulletX == enemyX) {
\nSystem.out.println(“Enemy Hit!”);
\nenemyY = 0;
\nenemyX = new Random().nextInt(WIDTH);
\nbulletY = -1;
\n}
\n}
\n}<\/p>\n