Defining routes like above is very tedious to maintain. To separate the routes from our main index.js file, we will use Express.Router. Create a new file called things.js and type the following in it.

Things.js

var express = require('express');
var router = express.Router();

router.get('/', function(req, res){
   res.send('GET route on things.');
});
router.post('/', function(req, res){
   res.send('POST route on things.');
});

//export this router to use in our index.js
module.exports = router;

server.js

var express = require('express');
var app = express();
// other file
var things = require('./things.js');
app.use('/things', things);
app.get('/', function(req, res){
    res.send('Hello Node JS');
});
app.post('/hello', function(req, res){
    res.send('You Just Called POST method');
    res.statusCode(200);
})
app.listen(3000);