redirect to 404 page in node js express

To redirect to a 404 page in Node.js Express, you can follow these steps:

First, import the Express module and create an instance of the Express application:

const express = require('express');
const app = express();

Create a middleware function to handle 404 errors. This function should be placed after all other routes and middleware in your application. It will be called if no other route or middleware matches the current request:

app.use((req, res, next) => {
  res.status(404).send('404: Page not found');
});

const port = 3000; // Or any other port number
app.listen(port, () => {
  console.log(`Server is running on port ${port}`);
});

Here's a breakdown of the steps:

Import the Express module and create an instance of the Express application. This allows you to use Express functions and methods in your application.
Create a middleware function using the app.use() method. This function takes three parameters: req (request), res (response), and next. In this case, we only need the res parameter. Inside the middleware function, we set the response status to 404 using res.status(404) and send a simple message indicating that the page was not found using res.send('404: Page not found'). This will be the response sent to the client when a 404 error occurs.
Start the server and listen for incoming requests on a specified port using the app.listen() method. In this example, we're using port 3000, but you can choose any available port. When the server starts, it will log a message indicating the port it's running on.

That's it! With these steps, you can redirect to a 404 page in Node.js Express.