socket.io random chatroom one to one

Question

so there is my code i am trying to create chatroom with Socket.io with rooms (one-to-one random chatroom) but i think there is bug because when i connect first two sockets it works perfectly but when i connect third socket it does not work anymore i think it is because of "numb++" but i don't know how to correct it because i have not many experience in rooms. i wanna implement : chat between 2 socket and when third client joins i wanna create second room and wait for forth socket to join to chat and etc. , and u i know i wanna one to one random chatroom like Omegle.

 var numb = 1;
 var chnm = io.of('/STchat')

 app.get('/STchat', function(req, res){

res.sendFile('C:\\Users\\tuna\\Desktop\\JUSTFOL\\views\\Tchat.html')

chnm.once('connect', function(socket){
  socket.join("room" + numb)
  console.log('made socket connection', socket.id);
chnm.in("room" + numb).clients(function(err, clients){
      if(clients.length > 2) {

     numb++
      }
});
socket.on('chat', function(data) {
 chnm.in("room" + numb).emit('chat',data)

  })
  socket.on('disconnect', function(){
    console.log('socket disconnected')
  });

}
});
app.get('/StvChat', function(req ,res){
res.sendFile(__dirname + '/views/VideoC.html');


});









var socket = io.connect('http://localhost:5000/STchat')

var message = document.getElementById('message');
handle = document.getElementById('handle');
btn = document.getElementById('send');
output = document.getElementById('output');
typing = document.createElement('p');
typing.className = "tycl";
input = document.getElementById("message");

$('form').submit(function(){


    socket.emit('chat',{
        message: message.value,

    });
    $('#message').val('');
    return false;
});
input.addEventListener("keyup", function(event) {
       event.preventDefault();

    if (event.keyCode === 13) {

      document.getElementById("send").click();
    }
  });

socket.on('chat', function(data){
  output.innerHTML += '<p>' +'  '+ data.message +'</p>' 
});

Answer 1

This was too long to fit in the comments so I have added as an answer. To clarify, here is an issue I am seeing in the way you are emitting the chat event. Lets walk through a scenario.

var numb = 1;

Two users (User A, and User B) connect to the socket and are put into room "room1". Now, numb should be incremented by your code and now numb will be == 2.

Now, User A (who is in "room1") emits a "chat" event. Here is the issue I see:

socket.on('chat', function(data) {
    chnm.in("room" + numb).emit('chat', data)

})

User A's chat event is emitted to "room2" but User A is in "room1". This happens because numb == 2 at this point in the scenario and you are using numb to emit that event, basically this is what happens chnm.in("room" + 2). User B does not get User A's emit, because it was sent to the wrong room (room2). If I misunderstood what you are trying to do please let me know.

EDIT: As requested here is some modifications to your code that I have tested locally with success. Two users per each room.

var numb = 1;
var chnm = io.of('/STchat');

app.get('/STchat', function(req, res) {

    res.sendFile('C:\\Users\\tuna\\Desktop\\JUSTFOL\\views\\Tchat.html');

    chnm.once('connect', function(socket) {

        // store the room in a var for convenience
        var room = "room" + numb;

        // join socket to the next open room
        socket.join(room);

        // store room on socket obj for use later - IMPORTANT
        socket.current_room = room;

        // log some stuff for testing
        console.log('made socket connection', socket.id);
        console.log("Joined room: ", socket.current_room);

        // Check room occupancy, increment if 2 or more
        chnm.in(room).clients(function(err, clients) {
            if (clients.length >= 2) {
                numb++;
            }
        });

        socket.on('chat', function(data) {
            // emit to that sockets room, now we use that current_room
            chnm.in(socket.current_room).emit('chat', data);
        });

        socket.on('disconnect', function() {
            console.log('socket disconnected');
        });
    });

});

app.get('/StvChat', function(req, res) {
    res.sendFile(__dirname + '/views/VideoC.html');
});