functions and handlers

cmd/hello-world/main.go

@@ -5,14 +5,30 @@ import (
 	"net/http"
 )
 
-func main() {
+const portNumber = ":8080"
-	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
-		n, err := fmt.Fprintf(w, "Hello world")
-		if err != nil {
-			fmt.Println(err)
-		}
-		fmt.Printf("Number of bytes written: %d\n", n)
-	})
 
-	_ = http.ListenAndServe(":8080", nil)
+// Home is the about page handler
+func Home(w http.ResponseWriter, r *http.Request) {
+	fmt.Fprintf(w, "This is the home page")
+}
+
+// About is the about page handler
+func About(w http.ResponseWriter, r *http.Request) {
+	sum := addValues(2, 2)
+	fmt.Fprintf(w, "This is the about page and 2 + 2 is %d", sum)
+}
+
+// addValues adds two integers and returns the sum
+func addValues(x, y int) int {
+	return x + y
+}
+
+// main is the main application function
+func main() {
+	http.HandleFunc("/", Home)
+	http.HandleFunc("/about", About)
+
+	fmt.Printf("Starting application on port %s\n", portNumber)
+
+	_ = http.ListenAndServe(portNumber, nil)
 }