I am new to Nodejs and working on Express js and now I am working on "middleware functions" for a specific route and I want to know "what is next used for", means after verifying what the "next" function can do? If we want to move/redirect to another function then how do we do that? What is "checkAuthentication"? This is my current code
const express = require('express'); const app = express(); // Custom middleware function const authMiddleware = (req, res, next) => { // Check if user is authenticated const isAuthenticated = checkAuthentication(req); if (isAuthenticated) { next(); } else { // User is not authenticated, send an unauthorized response res.status(401).send('Unauthorized'); } }; // Middleware function is applied to specific routes app.get('/protected', authMiddleware, (req, res) => { res.send('Protected Route'); }); // Route handler app.get('/', (req, res) => { res.send('Home Page'); }); // Start the server app.listen(3000, () => { console.log('Server is listening on port 3000'); });
Next is the callback function passed to the middleware function. You can find it under different names in different frameworks but the concept remains the same.
I will try to explain the middleware through your code itself.