Routing is a fundamental concept in web development that involves directing incoming HTTP requests to the appropriate handler functions based on the URL and HTTP method. In Go, routing is typically handled using third-party packages like gorilla/mux or the built-in net/http package. This section will cover the basics of routing, how to set up routes, and how to handle different HTTP methods.

1. Router: A router is responsible for matching incoming requests to the appropriate handler functions.
2. Route: A route defines a specific URL pattern and the handler function that should be executed when a request matches that pattern.
3. Handler Function: A function that processes an HTTP request and generates a response.

The net/http package provides basic routing capabilities. Here's how you can set up a simple router using net/http:

• http.HandleFunc("/", homeHandler): This line registers the homeHandler function to handle requests to the root URL (/).
• http.HandleFunc("/about", aboutHandler): This line registers the aboutHandler function to handle requests to the /about URL.
• http.ListenAndServe(":8080", nil): This line starts the HTTP server on port 8080.

gorilla/mux is a powerful routing package that provides more advanced routing capabilities. Here's how you can set up a router using gorilla/mux:

• r := mux.NewRouter(): This line creates a new router using gorilla/mux.
• r.HandleFunc("/", homeHandler).Methods("GET"): This line registers the homeHandler function to handle GET requests to the root URL (/).
• r.HandleFunc("/about", aboutHandler).Methods("GET"): This line registers the aboutHandler function to handle GET requests to the /about URL.
• http.ListenAndServe(":8080", r): This line starts the HTTP server on port 8080, using the gorilla/mux router.

In web development, different HTTP methods (GET, POST, PUT, DELETE) are used to perform different actions. Here's how you can handle different HTTP methods using gorilla/mux:

• r.HandleFunc("/resource", getHandler).Methods("GET"): This line registers the getHandler function to handle GET requests to the /resource URL.
• r.HandleFunc("/resource", postHandler).Methods("POST"): This line registers the postHandler function to handle POST requests to the /resource URL.
• r.HandleFunc("/resource", putHandler).Methods("PUT"): This line registers the putHandler function to handle PUT requests to the /resource URL.
• r.HandleFunc("/resource", deleteHandler).Methods("DELETE"): This line registers the deleteHandler function to handle DELETE requests to the /resource URL.

1. Create a new Go project.
2. Set up a router using gorilla/mux.
3. Create handler functions for the following routes:
   • /: Should return "Welcome to the Home Page!"
   • /about: Should return "This is the About Page."
   • /contact: Should return "Contact us at [email protected]"
4. Start the server on port 8080.

1. Not Specifying HTTP Methods: Always specify the HTTP methods for your routes to avoid unexpected behavior.
2. Incorrect URL Patterns: Ensure that your URL patterns are correctly defined to match the incoming requests.
3. Not Handling Errors: Always handle potential errors, such as failing to start the server.

• Use meaningful names for your handler functions to make your code more readable.
• Organize your routes logically, grouping related routes together.
• Consider using middleware for common tasks like logging, authentication, and error handling.

In this section, you learned about routing in Go, how to set up a router using both net/http and gorilla/mux, and how to handle different HTTP methods. You also completed a practical exercise to reinforce these concepts. In the next section, you will learn about middleware and how to use it to enhance your web applications.