Obtain a list of clients connecting to Socket.io from the client

var http=require("http");
var server = http.createServer(function(req,res){
    res.write("Hello World!""); // ・・・　①
    res.end();//...2
});

// Preparing Socketio
vario=require('socket.io')(server);

// Client Connection Processing
io.on('connection', function(socket){
    console.log("client connected!!!")

    // Client Disconnect Action
    socket.on('disconnect', function(){
        console.log("client disconnected!!")
    });
    // Receive from client (socket.on)
    socket.on("from_client", function(obj){
        console.log(obj)
    });
});

server.listen (8080);

// Obtaining Connected Client Information    
var clients =io.sockets.clients();
// Retrieve the number of connected clients 
var count = clients.length;

if(count!==0){
    for(vari=0;i<count;i++){
        res.write(clients[i]);
        res.write("</br>");
        res.end();
    }
}