How can I use middleware with route parameters in my web application?

How can I use middleware with route parameters in my web application?

You can use middleware to process route parameters by defining a middleware function that extracts and validates them before reaching your route handler.

Can you give me an example of how to implement this in Express.js?

Sure! In Express.js, you can create a middleware function like this:

app.use('/:id', (req, res, next) => {
    const id = req.params.id;
    if (!isValidId(id)) {
        return res.status(400).send('Invalid ID');
    }
    next();
});

What if I want to use multiple middleware functions?

You can chain multiple middleware functions by passing them in the order you want them to execute. For example:

app.use('/:id', validateId, logRequest, (req, res) => {
    res.send(`ID is valid: ${req.params.id}`);
});