stringer.go https://tour.golang.org/methods/18

stringer.go

// Solution to exercise at https://tour.golang.org/methods/18

// Exercise: Stringers
// Make the IPAddr type implement fmt.Stringer to print the address as a dotted quad.
// For instance, IPAddr{1, 2, 3, 4} should print as "1.2.3.4".

package main

import (
	"fmt"
	"strings"
	"strconv"
)

type IPAddr [4]byte

// TODO: Add a "String() string" method to IPAddr.

func (ipv4 IPAddr) String() string {
	var dq []string
	for _,b := range ipv4 {
		dq = append(f, strconv.Itoa(int(b)))
	}
	return strings.Join(dq, ".")
}

func main() {
	hosts := map[string]IPAddr{
		"loopback":  {127, 0, 0, 1},
		"googleDNS": {8, 8, 8, 8},
	}
	for name, ip := range hosts {
		fmt.Printf("%v: %v\n", name, ip)
	}
}