From a74265e4dc5b69614fa9bf9e633cb99cc3a06f47 Mon Sep 17 00:00:00 2001
From: Sebastian Steger <s.steger@hs-mannheim.de>
Date: Mon, 13 Oct 2025 12:36:59 +0200
Subject: [PATCH] documentation for methods and interfaces

---
 go/02-next-level/00-methods.go    | 6 ++++--
 go/02-next-level/01-interfaces.go | 6 ++++++
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/go/02-next-level/00-methods.go b/go/02-next-level/00-methods.go
index a005976..ae1a6ac 100644
--- a/go/02-next-level/00-methods.go
+++ b/go/02-next-level/00-methods.go
@@ -6,12 +6,14 @@ type Counter struct {
 	value int
 }
 
-// pointer receiver
+// pointer receiver. The method operates directly on the object c points to
+// Use a pointer receiver whenever the object needs to be modified.
 func (c *Counter) Increment() {
 	c.value++
 }
 
-// value receiver
+// value receiver. The method operates on copy of object c. Use a value
+// receiver when the object does not need to be modified in the method.
 func (c Counter) String() string {
 	return fmt.Sprintf("Counter value: %d", c.value)
 }
diff --git a/go/02-next-level/01-interfaces.go b/go/02-next-level/01-interfaces.go
index 6a6e25f..c0eb97f 100644
--- a/go/02-next-level/01-interfaces.go
+++ b/go/02-next-level/01-interfaces.go
@@ -14,12 +14,14 @@ type rect struct {
 	width, height float64
 }
 
+// Ensure that rect implements the geometry interface
 var _ geometry = rect{}
 
 type circle struct {
 	radius float64
 }
 
+// Ensure that circle implements the geometry interface
 var _ geometry = circle{}
 
 func (r rect) area() float64 {
@@ -36,12 +38,16 @@ func (c circle) perim() float64 {
 	return 2 * math.Pi * c.radius
 }
 
+//Metods demonstrates how to use an interface
 func measure(g geometry) {
 	fmt.Println(g)
 	fmt.Println(g.area())
 	fmt.Println(g.perim())
 }
 
+
+//Method demonstrates casting an interface to a concrete type. 
+//Should be avoided in practice whenever possible.
 func detectCircle(g geometry) {
 	if c, ok := g.(circle); ok {
 		fmt.Println("circle with radius", c.radius)