stringer.go

package main

import ("fmt")

type IPAddr [4]byte

// TODO: Add a "String() string" method to IPAddr.
func (ip IPAddr ) String() string{
    return fmt.Sprintf("%v.%v.%v.%v", ip[0], ip[1],ip[2],ip[3])
}
func main() {
	addrs := map[string]IPAddr{
		"loopback":  {127, 0, 0, 1},
		"googleDNS": {8, 8, 8, 8},
	}
	for n, a := range addrs {
		fmt.Printf("%v: %v\n", n, a)
	}
}