package main

import "fmt"

type Date struct {
	Year  int
	Month int
	Day   int
}

func (d Date) String() string {
	return fmt.Sprintf("%d/%d/%d", d.Month, d.Day, d.Year)
}

type Student struct {
	Name     string
	ID       string
	birthday Date
}

func (s Student) String() string {
	return fmt.Sprintf("<<Name:%s Id:%s BDay:%s>>", s.Name, s.ID, s.birthday)
}

func main() {
	d := Date{1996, 3, 4}
	fmt.Println(d)

	s1 := Student{"Mary", "123321", Date{2003, 2, 1}}
	fmt.Printf("%v\n%+v\n", s1, s1)

	s2 := Student{birthday: Date{2002, 3, 4}, ID: "654321", Name: "Gertrude"}
	fmt.Println(s2)

	mp := make(map[string]Student)
	mp[s2.ID] = s2
	mp[s1.ID] = s1
	fmt.Println(mp)

}