public sessionId;

constructor(){

var socket = io.connect('http://**.***.***.***:****');

socket.on('connect', function (data) {
  console.log('user connected');
  socket.emit('add user', { userId: uid });
});

socket.on('create channel', function (data) {

  console.log(data);
  this.sessionId = data.sessionId;    //error
  this.function();                    //error

  socket.emit('feedback', { received: true });
});
}


function(){}