如何在 Node JS 变量上存储 HTML 表单输入？

Question

I am unable to set the values of HTML form inputs on to my Node JS variable. Below is my JS code where I am not able to set the values of variables "hostname" and "port" which will in turn concatenate to a new variable called url.

console.log(url) prints just mongodb://:. which suggests that my HTML form values are not being stored in my Node JS variables.

var express     = require('express');        // call express
var app         = express();                 // define our app using express
var bodyParser  = require('body-parser');
var router      = express.Router();  

app.use(bodyParser.urlencoded({ extended: true }));
app.use(bodyParser.json());

var port = process.env.PORT || 8080;        

var router = express.Router();              

const dbname    = "admin";

var hostname ='';
var port2 ='';

app.post('/', function(req, res){ 
    hostname = req.body.hostname;
    port2 = req.body.port2;
});

var url ="mongodb://"+hostname+":"+port2;

Below is my html which is handling the form inputs

    <form class="clr-form" action="/" method="POST">
        <input type="text" name="hostname" placeholder="Enter Host Name" class="clr-input"> <br/>
        <input type="text" name="port2" placeholder="Enter Port" class="clr-input"><br/>
        <input type="submit" value="Submit" />
    </form>

Answer 1

You don't need to redeclare the port2 again

var port2 ='';

app.post('/', function(req, res){ 
    var hostname = req.body.hostname;
    port2 = req.body.port2;
});

var url ="mongodb://"+hostname+":"+port2;

Answer 2

var hostname ='';
var port2 ='';

app.post('/', function(req, res){ 
     hostname = req.body.hostname;
     port2 = req.body.port2;
});

You should not declare variables inside the function again if you want to assign body values to your variables which one you will be using outside of scope.