reorganize: starting with funcs

25-functions/01-basics/bad.go

@@ -0,0 +1,26 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+package main
+
+import "fmt"
+
+func showN() {
+	if N == 0 {
+		fmt.Println("showN       : N is zero, increment it.")
+		return
+	}
+	fmt.Printf("showN       : N = %d\n", N)
+}
+
+func incrN() {
+	N++
+}
+
+// you cannot declare a function within the same package with the same name
+// func incrN() {
+// }

25-functions/01-basics/main.go

@@ -0,0 +1,33 @@
+// For more tutorials: https://blog.learngoprogramming.com
+//
+// Copyright © 2018 Inanc Gumus
+// Learn Go Programming Course
+// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
+//
+
+//
+// You need run this program like so:
+//   go run .
+//
+// This will magically pass all the go files in the current directory to the
+// Go compiler.
+//
+//
+// BUT NOT like so:
+//   go run main.go
+//
+// Because, the compiler needs to see global.go too
+// It can't magically find global.go — what you give is what you get.
+//
+
+package main
+
+// N is a shared counter which is BAD
+var N int
+
+func main() {
+	showN()
+	incrN()
+	incrN()
+	showN()
+}