Go map function

package main

import (
	"fmt"
)

type (
	user struct {
		ID   int    `json:"id"`
		Name string `json:"name"`
	}
)

var (
	users = map[int]*user{}
)

func main() {

	var map1 map[string]string = map[string]string{}
	fmt.Println(map1)
	//map[]

	var map2 = make(map[string]string)
	fmt.Println(map2)
	//map[]

	map3 := map[string]string{}
	fmt.Println(map3)
	//map[]

	var map4 map[string]string = map[string]string{"one": "apple", "two": "orange"}
	fmt.Println(map4)
	//map[two:orange one:apple]

	map5 := map[string]string{"one": "apple", "two": "orange"}
	fmt.Println(map5)
	//map[two:orange one:apple]

	map6 := map[string]string{
		"one": "apple",
		"two": "orange",
	}
	fmt.Println(map6)
	//map[two:orange one:apple]

	map7 := make(map[string]string)
	map7["one"] = "apple"
	map7["two"] = "orange"
	fmt.Println(map7)
	//map[two:orange one:apple]

	map8 := map[int]string{
		1: "apple",
		2: "orange",
	}
	fmt.Println(map8)
	//map[1:apple 2:orange]

	if val, ok := map8[1]; ok {
		fmt.Printf("exists %#v", val)
	} else {
		fmt.Printf("not exists")
	}
	//exists "apple"

	u := &user{
		ID:   1,
		Name: "mike",
	}
	users[u.ID] = u
	fmt.Println(users[1])
	//&{1 mike}

}