Using Custom Middleware in Express.js

1. What is Middleware?
   Middleware is an important part of Express.js. It's like a helper that processes requests before they reach the main part of your application.

2. How to Create Middleware:

   • Make a Middleware Function: This function needs three parts: req, res, and next.
   • Add it with app.use(): You can set up your middleware to work for all requests or just for certain ones.

3. Why Use Middleware?
   Studies show that middleware can make your app faster. It can cut down response times by up to 30%. So instead of taking an average of 200 milliseconds, it can sometimes only take 140 milliseconds!

4. Here’s a Simple Example:

   app.use((req, res, next) => {
       console.log('Middleware has run');
       next();
   });
   

Using middleware helps keep your app running smoothly and quickly!