add: questions and exercises for the if statement

11-if/exercises/08/solution/main.go

@@ -0,0 +1,36 @@
+// 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() {
+	if len(os.Args) != 2 {
+		fmt.Println("Give me a year number")
+		return
+	}
+
+	year, err := strconv.Atoi(os.Args[1])
+	if err != nil {
+		fmt.Printf("%q is not a valid year.\n", os.Args[1])
+		return
+	}
+
+	if year%4 == 0 && (year%100 != 0 || year%400 == 0) {
+		fmt.Printf("%d is a leap year.\n", year)
+	} else {
+		fmt.Printf("%d is not a leap year.\n", year)
+	}
+}
+
+// Review the original source code here:
+// https://github.com/golang/go/blob/ad644d2e86bab85787879d41c2d2aebbd7c57db8/src/time/time.go#L1289