Socket.io Join Leave Rooms And Check socket is connected with Room

when we use Socket, we need Know About join & Leave Room.

 io.on('connection', function(socket){  
  socket.join('game');  
 });  

Here socket join "game" room.

"game" is room name. you may use any number as room name.

Let, Send Some Message to Players which are connected with "game" room.

 // sending to all clients in 'game' room except sender  
 socket.to('game').emit('niceGame', "let's play a game");  

Here "niceGame" is event Name.

now we Print All Room which are connected with socket.

Print all rooms which are connected With this.socket

 console.log(socket.adapter.rooms);  

whenever you want to check your socket is connected with Room.

 if(self.socket.adapter.rooms['game']){  
  console.log("you are in room");  
 }  

Thanks.