How to uniquely identify a socket with Node.js

Question

TLDR; How to identify sockets in event based programming model.

I am just starting up with node.js , in the past i have done most of my coding part in C++ and PHP s

Answer 1

if you found this question by looking for socket.io unique ids that you can use to differentiate between sockets on the client-side (just like i did), then here is a very simple answer:

var id = 0; //initial id value
io.sockets.on('connection', function(socket) {

    var my_id = id; //my_id = value for this exact socket connection
    id++; //increment global id for further connnections

    socket.broadcast.emit("user_connected", "user with id " + my_id + "connected");
}

on every new connection the id is incremented on the serverside. this guarantees a unique id.
I use this method for finding out where a broadcast came from on the clientside and saving data from concurrent sockets.

for example:

server-side

var my_coords = {x : 2, y : -5};
socket.broadcast.emit("user_position", {id: my_id, coord: my_coords});  

client-side

user = {};
socketio.on("user_position", function(data) {
    if(typeof user[data.id] === "undefined")
        user[data.id] = {};

    user[data.id]["x"] = data.coord.x;
    user[data.id]["y"] = data.coord.y;
});