get the ? in express code example

Example 1: express get url parameters

app.get('/path/:name', function(req, res) {
  res.send("tagId is set to " + req.params.name);
});

Example 2: express route parameters

Route path: /users/:userId/books/:bookId
Request URL: http://localhost:3000/users/34/books/8989
req.params: { "userId": "34", "bookId": "8989" }