Which middleware is commonly used to parse incoming request bodies in Express?express.urlencoded()express.bodyParser()body-parserbodyHandler

The middleware commonly used to parse incoming request bodies in Express is body-parser.

Here's a step-by-step guide on how to use it:

1. First, you need to install the body-parser middleware. You can do this using npm (Node Package Manager) by running the following command in your terminal: npm install body-parser.

2. Once installed, you need to import it into your file. You can do this by adding the following line at the top of your server file: const bodyParser = require('body-parser').

3. After importing, you need to use body-parser in your application. This can be done by adding the following lines:

   app.use(bodyParser.json()); - This line tells the system that you want to use JSON.

   app.use(bodyParser.urlencoded({ extended: true })); - This line tells the system that you want to use simple algorithm for shallow parsing (false) or complex algorithm for deep parsing that can deal with nested objects (true).

Now, body-parser will parse incoming request bodies in a middleware before your handlers, available under the req.body property.