How can i get user id serverside?

Question

I am making a node.js application with express and i need to get user ID. I need something like "req.userID", to use like that:

var counter=0;
var user = new Array();

router.get("/", function(req, res) {
 var aux=0;
 user.forEach(i => { 
  if(i != req.userID)
   var aux++;
  else console.log("User exist!");
  if(aux === user.length)
   user.push(req.userID);
 })

});

Answer 1

“req.connection.remoteAddress”谢谢ObsoleteAwareProduce，这正是我要找的：D