socket.rooms is a useless object

This is concerning the socket.rooms object, documented as:

A hash of strings identifying the rooms this client is in, indexed by room name.

I don’t know what that means, but the example is clear:

io.on('connection', function(socket){
  socket.join('room 237', function(){
    console.log(socket.rooms); // [ <socket.id>, 'room 237' ]
    io.to('room 237', 'a new user has joined the room'); // broadcast to everyone in the room
  });
});

When I run console.log(socket.rooms);, I want that pretty array (so I can slice off <socket.id> and get just the rooms), but I get this ugly object back:

io.on('connection', function(socket){
  socket.join('room 237', function(){
    console.log(socket.rooms); // { <socket.id>: '<socket.id>', 'room 237': 'room 237' }
  });
});

… which I then have to turn into an array with .keys() and then pick out the socket.id by hand (since it might not be first).

Is this a bug? I’m using 1.7.3.

[chargingsleipnir]

Yah this seems unnecessarily complicated. I’m really struggling to understand why the user’s socket id constitutes being a “room”?, or why key:value pairs are needed. It just needs to be a list - whatever rooms are present, you are in, done.

['room1', 'room2', 'room3']

And as above, io.rooms to get them all, either, also as a string array, or in this case as an object with room names as keys and an array of socket ids as their value.

{ room1: ['id1', 'id2', 'id3'], room2: ['id4', 'id5', 'id6'] }

[StefansArya]

I think the main reason is the lookup performance. For the example, when a user was joined 100 room it would be more faster to use object lookup to find out if he was joined a room rather than iterating array value.

Refer to my answer on stackoverflow

{
    "room1":"room1",
    "room2":"room2",
    ...
    "room100":"room100"
}

To check if user has joined a room just a simple like this: if(socket.rooms[roomID]) return true;

If it’s array type then we need to use indexOf or iterate every array: if(socket.rooms.indexOf(roomID) != -1) return true;

But I totally agree if the the key value is changed to a boolean: { room1: true, ... , room100: true }

It may help saving some memory usage