add: switch statement exercises

12-switch/exercises/05-days-in-month/solution/main.go

@@ -0,0 +1,44 @@
+// 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"
+	"strings"
+	"time"
+)
+
+func main() {
+	if len(os.Args) != 2 {
+		fmt.Println("Give me a month name")
+		return
+	}
+
+	year := time.Now().Year()
+	leap := year%4 == 0 && (year%100 != 0 || year%400 == 0)
+
+	days, month := 28, os.Args[1]
+
+	switch strings.ToLower(month) {
+	case "april", "june", "september", "november":
+		days = 30
+	case "january", "march", "may", "july",
+		"august", "october", "december":
+		days = 31
+	case "february":
+		if leap {
+			days = 29
+		}
+	default:
+		fmt.Printf("%q is not a month.\n", month)
+		return
+	}
+
+	fmt.Printf("%q has %d days.\n", month, days)
+}