Check if room exists/if anyone is in room

[Especially]

Is there a way to check whether or not a room exists before using emitter->to(room)->emit()? If there's no one in room then i'd like PHP to execute a different script, is there any way to handle this??

[amolmk]

You can simply check like this
socketio.sockets.adapter.rooms[roomId]

This returns you a object with sId e.g.
{"1sEAEIZeuMgdhF35AAAA":true}