Socket#in

Socket#in(room:String):Socket

Sets a modifier for a subsequent event emission that the event will only be broadcasted to sockets that have joined the given room.

To emit to multiple rooms, you can call to several times.

var io = require('socket.io')();
io.on('connection', function(socket){
  socket.to('others').emit('an event', { some: 'data' });
});