learngo/11-if/exercises/08-simplify-leap-year/solution/main.go

// Copyright © 2018 Inanc Gumus
// Learn Go Programming Course
// License: https://creativecommons.org/licenses/by-nc-sa/4.0/
//
// For more tutorials  : https://learngoprogramming.com
// In-person training  : https://www.linkedin.com/in/inancgumus/
// Follow me on twitter: https://twitter.com/inancgumus

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