update book code

eBook/examples/chapter_6/side_effect.go

@@ -1,17 +1,18 @@
-package main
-
-import (
-    "fmt"
-)
-
-// this function changes reply:
-func Multiply(a, b int, reply *int) {
-    *reply = a * b
-}
-
-func main() {
-    n := 0
-    reply := &n
-    Multiply(10, 5, reply)
-    fmt.Println("Multiply:", *reply) // Multiply: 50
-}
+// side_effect.go
+package main
+
+import (
+	"fmt"
+)
+
+func Multiply(a, b int, reply *int) {
+	*reply = a * b
+}
+
+func main() {
+	n := 0
+	reply := &n
+	Multiply(10, 5, reply)
+	fmt.Println("Multiply:", *reply) // Multiply: 50
+	fmt.Println("Multiply:", n) // Multiply: 50
+}