How do I use route parameters in Express.js?

How do I use route parameters in Express.js?

In Express.js, route parameters are named URL segments that can be used to capture values from the URL. You define them in your route path using a colon. For example, in the route /users/:id, :id is a route parameter.

Can you give me an example of how to access the route parameter in my code?

Sure! Here's a simple example:

app.get('/users/:id', (req, res) => {
    const userId = req.params.id;
    res.send(`User ID is: ${userId}`);
});

In this code, req.params.id retrieves the value of the id parameter from the URL.

What if I want to use multiple route parameters?

You can define multiple route parameters by separating them with slashes. For example, /users/:id/posts/:postId allows you to capture both id and postId. You can access them using req.params.id and req.params.postId.

Is there a way to validate these parameters?

Yes, you can validate route parameters using middleware or libraries like express-validator. You can check if the parameters meet certain criteria before processing the request.