In this tutorial, we will walk through the process of building a real-time multiplayer game matchmaking system using Express.js. This system will allow players to find opponents and join game sessions in real-time.

Prerequisites

Before we get started, make sure you have the following prerequisites installed:

• Node.js and npm
• Express.js
• Socket.io

Setting Up the Project

1. Create a new directory for your project and navigate to it using the command line.
2. Initialize a new Node.js project by running npm init and following the prompts.
3. Install Express.js and Socket.io by running npm install express socket.io.

Building the Matchmaking System

1. Create a new server.js file in the root directory of your project.
2. Import the required modules:

   const express = require('express');
   const http = require('http');
   const socketio = require('socket.io');
   

3. Set up Express.js: ```javascript const app = express(); const server = http.createServer(app); const io = socketio(server);

server.listen(PORT, () => { console.log(Server running on port ${PORT}); });

4. Implement the matchmaking logic:
```javascript
const waitingPlayers = [];

io.on('connection', (socket) => {
  // Add players to the waiting list
  waitingPlayers.push(socket);

  // Remove player from the waiting list when they disconnect
  socket.on('disconnect', () => {
    const index = waitingPlayers.indexOf(socket);
    if (index !== -1) {
      waitingPlayers.splice(index, 1);
    }
  });

  // Check for matching players when enough players are in the waiting list
  if (waitingPlayers.length >= 2) {
    const players = waitingPlayers.splice(0, 2);

    // Create a new game session and notify the players
    const gameSession = {
      id: generateGameSessionId(),
      players,
    };

    players.forEach((player) => {
      player.emit('gameMatched', gameSession);
    });
  }
});

function generateGameSessionId() {
  // Generate a unique game session ID
  // You can use a library like shortid or generate a UUID
}

1. Add the necessary client-side code to connect to the server and handle the gameMatched event.

Conclusion

By following this tutorial, you have implemented a real-time multiplayer game matchmaking system using Express.js. Players can now join game sessions and play against opponents in real-time. You can further enhance this system by adding game-specific logic and handling game sessions using a database.

#gamedevelopment #expressjs