Express.js – req.acceptsLanguage() Method

The req.acceptsLanguage() method returns the first accepted language out of the specified languages based on the request's Accept-Language HTTP header field. This method returns 'false' if none of the specified language is accepted.

Syntax

req.acceptsLanguage ( lang, [...] )

Example 1

Create a file with the name "reqLang.js" and copy the following code snippet. After creating the file, use the command "node reqLang.js" to run this code as shown in the example below −

// req.acceptsLanguage(lang, [...]) Method Demo Example
// Importing the express module
var express = require('express');

// Initializing the express and port number
var app = express();

// Initializing the router from express
var router = express.Router();
var PORT = 3000;

// Defining an endpoint
app.get('/api', function (req, res) {
   console.log(req.acceptsLanguages('en-IN'));
   console.log(req.get('accept-language'));
   res.end();
});
app.listen(PORT, function(err){
   if (err) console.log(err);
   console.log("Server listening on PORT", PORT);
});

Hit the Endpoint "localhost:3000/api" with a GET request and set the following property in the header: Accept-Language = en-IN

Output

C:\home\node>> node reqLang.js
Server listening on PORT 3000
en-IN
en-IN

Example 2

Let's take a look at one more example.

// req.acceptsLanguage(lang, [...]) Method Demo Example
// Importing the express module
var express = require('express');

// Initializing the express and port number
var app = express();

// Initializing the router from express
var router = express.Router();
var PORT = 3000;

// Defining an endpoint
app.get('/api', function (req, res) {
   console.log("Is Language of Accepted type: ", req.acceptsLanguages('en-IN', 'en-US'));
   console.log("Language passed -- ", req.get('accept-language'));
   res.end();
});
app.listen(PORT, function(err){
   if (err) console.log(err);
   console.log("Server listening on PORT", PORT);
});

Output

Hit the Endpoint "localhost:3000/api" with a GET Request and set the following property in the headers: Accept-Language = fr-CH

C:\home\node>> node reqLang.js
Server listening on PORT 3000
Is Language of Accepted type: false
Language passed -- fr-CH