how to register only one socket.io client event listener code example

Example 1: socket io connect to namespace

var io  = require('socket.io')(http, { path: '/myapp/socket.io'});

io
.of('/my-namespace')
.on('connection', function(socket){
    console.log('a user connected with id %s', socket.id);

    socket.on('my-message', function (data) {
        io.of('my-namespace').emit('my-message', data);
        // or socket.emit(...)
        console.log('broadcasting my-message', data);
    });
});

Example 2: socket.io client send data node js server

var socket = io.connect('http://localhost');
socket.emit('my other event', { my: 'data' });
//server side
io.sockets.on('connection', function (socket) {
  socket.on('my other event', function (data) {
    console.log(data);
  });
});
//sending data from the user via a socket.io
socket.on("test", function (data) {
    data.forEach(obj => {
        console.log("Yer : " + obj.yer + ", Lat : " + obj.lat + ", Long : " + obj.lng);
    })
});