express what route came from code example

Example 1: node js express url parameters

// http://localhost:8080/api/1
app.get('/api/:version', function(req, res) {
    res.send(req.params.version);
});

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" }