Add first exercices of chapter 07

chapter_07/exercise_7.01/main.go

@@ -0,0 +1,34 @@
+package main
+
+import "fmt"
+
+type Speaker interface {
+  Speak() string
+}
+
+type person struct {
+  name      string
+  age       int
+  isMarried bool
+}
+
+func main() {
+
+  p := person{name: "Cailyn", age: 42, isMarried: false}
+  fmt.Println(p.Speak())
+  fmt.Println(p)
+
+}
+
+func (p person) String() string {
+
+  return fmt.Sprintf("%v (%v years old).\nMarried status: %v",
+    p.name, p.age, p.isMarried)
+
+}
+
+func (p person) Speak() string {
+
+  return "Hi, my name is " + p.name
+
+}

chapter_07/exercise_7.02/main.go

@@ -0,0 +1,62 @@
+package main
+
+import "fmt"
+
+type Shape interface {
+  Area() float64
+  Name() string
+}
+
+type triangle struct {
+  base   float64
+  height float64
+}
+
+type rectangle struct {
+  length float64
+  width  float64
+}
+
+type square struct {
+  side float64
+}
+
+func (t triangle) Area() float64 {
+  return (t.base * t.height) / 2
+}
+
+func (t triangle) Name() string {
+  return "triangle"
+}
+
+func (r rectangle) Area() float64 {
+  return r.length * r.width
+}
+
+func (r rectangle) Name() string {
+  return "rectangle"
+}
+
+func (s square) Area() float64 {
+  return s.side * s.side
+}
+
+func (s square) Name() string {
+  return "square"
+}
+
+func printShapeDetails(shapes ...Shape) {
+  for _, item := range shapes {
+    fmt.Printf("The area of %s is %.2f\n", item.Name(), item.Area())
+  }
+}
+
+func main() {
+
+  t := triangle{15.5, 20.1}
+  r := rectangle{20, 10}
+  s := square{10}
+
+  printShapeDetails(t, r, s)
+
+}