Socket IO Rooms: Get list of clients in specific room

Question

I'm trying to display a list of clients in a specific room. I just want to show their username, and not their socket id.

This where I'm at:

socket.set('nickname', "Earl");   socket.join('chatroom1'); console.log('User joined chat room 1);  var roster = io.sockets.clients('chatroom1'); for ( i in roster ) {    console.log('Username: ' + roster[i]);    } 

Haven't had any luck getting it to list Socket IDs or anything. Would like it to return the nicknames however.

Answer 1

In socket.IO 3.x

New to version 3.x is that connected is renamed to sockets and is now an ES6 Map on namespaces. On rooms sockets is an ES6 Set of client ids.

//this is an ES6 Set of all client ids in the room const clients = io.sockets.adapter.rooms.get('Room Name');  //to get the number of clients in this room const numClients = clients ? clients.size : 0;  //to just emit the same event to all members of a room io.to('Room Name').emit('new event', 'Updates');  for (const clientId of clients ) {       //this is the socket of each client in the room.      const clientSocket = io.sockets.sockets.get(clientId);       //you can do whatever you need with this      clientSocket.leave('Other Room')  } 

In socket.IO 1.x through 2.x

Please refer the following answer: Get list of all clients in specific room. Replicated below with some modifications:

const clients = io.sockets.adapter.rooms['Room Name'].sockets;     //to get the number of clients in this room const numClients = clients ? Object.keys(clients).length : 0;  //to just emit the same event to all members of a room io.to('Room Name').emit('new event', 'Updates');  for (const clientId in clients ) {       //this is the socket of each client in the room.      const clientSocket = io.sockets.connected[clientId];       //you can do whatever you need with this      clientSocket.leave('Other Room') } 

Answer 2

Instead of going deep in socket/io object , You can use simple and standard way :

io.in(room_name).clients((err , clients) => {     // clients will be array of socket ids , currently available in given room }); 

For more detail DO READ