Initial commit

11-if/04-short-if/04-scope-shadowing/01-shadowing/main.go

@@ -0,0 +1,37 @@
+// 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"
+	"os"
+	"strconv"
+)
+
+func main() {
+	// UNCOMMENT THIS TO SEE IT IN ACTION:
+	// var n int
+
+	if a := os.Args; len(a) != 2 {
+		fmt.Println("Give me a number.")
+	} else if n, err := strconv.Atoi(a[1]); err != nil {
+		// else if here shadows the main func's n
+		// variable and it declares it own
+		// with the same name: n
+
+		fmt.Printf("Cannot convert %q.\n", a[1])
+	} else {
+		fmt.Printf("%s * 2 is %d\n", a[1], n*2)
+	}
+
+	// n here belongs to the main func
+	// not to the if statement above
+
+	// UNCOMMENT ALSO LINES BELOW TO SEE IT IN ACTION:
+	// fmt.Printf("n is %d. 👻 👻 👻 - you've been shadowed ;-)", n)
+}