Sending Response to All Clients Except Sender

To broadcast a message to all connected clients, the io.sockets.emit() function is used. However, when you want to exclude the sender from receiving the broadcast, you may wonder about a more straightforward approach than checking the sender's ID on the client-side.

In Socket.IO, the socket.broadcast property provides a solution for this scenario. By using socket.broadcast.emit(), you can send a message to all clients except the sender. Here's an example:

socket.on('cursor', function(data) {
  socket.broadcast.emit('response', data);
});

In this example, when a client sends a 'cursor' event, the server broadcasts the received data to all other connected clients, excluding the sender.

Here's a summary of Socket.IO emit functions for your reference:

• socket.emit(): Sends a message to the sender-client only.
• io.emit(): Sends a message to all clients, including the sender.
• socket.broadcast.emit(): Sends a message to all clients except the sender.
• socket.broadcast.to(): Sends a message to all clients in a specific room or channel, except the sender.
• socket.to(): Sends a message to the sender-client, only if they are in a specific room or channel.
• io.in(): Sends a message to all clients in a specific room or channel, including the sender.
• socket.broadcast.to(socketid): Sends a message to a specific client ID.
• io.of(): Sends a message to all clients in a specific namespace, including the sender.