My solution to Go's Tour Exercise: Stringers

exercise-stringer-solution.go

package main

import "fmt"

type IPAddr [4]byte

// Problem: Add a "String() string" method to IPAddr.
// Solution:
func (ip IPAddr) String() string {
	return fmt.Sprintf("%v.%v.%v.%v", ip[0], ip[1], ip[2], ip[3])
}

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)
	}
}

Go playground

Is there a way to use strings.Join()? the unfortunate thing is that this function does not automatically cast the byte to a string which it requires.

Is there a way to use strings.Join()? the unfortunate thing is that this function does not automatically cast the byte to a string which it requires.

func (i IPAddr) String() string {
	a:= make([]string, 0, 4)
	for _, ip := range i {
		a = append(a, strconv.Itoa(int(ip)))
	}
	return strings.Join(a, ".")
}