add: type switch

interfaces/06-empty-interface/empty/main.go

@@ -0,0 +1,29 @@
+// 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 main() {
+	// Let's create a variable using the empty interface type.
+	var any interface{}
+
+	// The variable can accept any type of value.
+	any = []int{1, 2, 3}
+	any = map[int]bool{1: true, 2: false}
+	any = "hello"
+	any = 3
+
+	// You can't multiply the last number.
+	// Reason: `any` is an `interface{}`, it's not a number.
+	// any = any * 2
+	// any = int(any) * 2
+
+	any = any.(int) * 2
+	fmt.Println(any)
+}