Example of chat function of nodejs simply implementing TCP server and client

var net = require('net');
var server = ();
//Aggregate all clientsvar sockets = [];
//Accept new client connection('connection', function(socket){
  ('got a new connection');
  (socket);
  //Read data from the connection  ('data', function(data){
    ('got data:', data);
    //Broadcast data    //Whenever a connected user enters data, the data will be broadcast to all other connected users    (function(otherSocket){
      if (otherSocket !== socket){
        (data);
      }
    });
    //Delete closed connection    ('close', function(){
      ('connection closed');
      var index = (socket);
      (index, 1);
    });
  });
});
('error', function(err){
  ('Server error:', );
});
('close', function(){
  ('Server closed');
});
(4000);

var net = require('net');
var port = 4000;
var quitting = false;
var conn;
var retryTimeout = 3000;  //Three seconds, define three seconds and reconnect after re-connectionvar retriedTimes = 0;  //Record the number of reconnectionsvar maxRetries = 10;  //Reconnect at most ten times(); //The stream accepts the user's keyboard input. This readable stream is in a pause state when initialized. Call the resume() method on the stream to restore the stream('data', function(data){
  if (().trim().toLowerCase() === 'quit'){
    quitting = true;
    ('quitting');
    ();
    ();
  } else {
    (data);
  }
});
// When connecting, set to connect up to ten times, and turn on the timer before connecting for three seconds.(function connect() {
  function reconnect() {
    if (retriedTimes >= maxRetries) {
      throw new Error('Max retries have been exceeded, I give up.');
    }
    retriedTimes +=1;
    setTimeout(connect, retryTimeout);
  }
  conn = (port);
  ('connect', function() {
    retriedTimes = 0;
    ('connect to server');
  });
  ('error', function(err) {
    ('Error in connection:', err);
  });
  ('close', function() {
    if(! quitting) {
      ('connection got closed, will try to reconnect');
      reconnect();
    }
  });
  //Print  (, {end: false});
})();