A Tour of Go Exercise: Stringers

exercise-stringer.go

package main

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

type IPAddr [4]byte

func (ip IPAddr) String() string {
	s := make([]string, len(ip))
	for i, val := range ip {
		s[i] = strconv.Itoa(int(val))
	}	
	return strings.Join(s, ".")
}

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)
	}
}

package main

import "fmt"

type IPAddr [4]byte

// TODO: Add a "String() string" method to IPAddr.
func (i IPAddr) String() string {
	return fmt.Sprintf("%v.%v.%d.%d", i[0], i[1], i[2], i[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)
	}
}

package main

import "fmt"

type IPAddr [4]byte

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

func (ip IPAddr) String() (s string) {
	for _, v := range ip {
		s += fmt.Sprintf("%v.", v)
	}
	
	s = s[:len(s)-1]
	return
}

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)
	}
}

Hello from Pythonists 😎

func (ip IPAddr) String() string {
	return strings.Join(strings.Split(strings.Trim(fmt.Sprint([len(ip)]byte(ip)), "[]"), " "), ".")
}

Hello from Pythonists 😎

func (ip IPAddr) String() string {
	return strings.Join(strings.Split(strings.Trim(fmt.Sprint([len(ip)]byte(ip)), "[]"), " "), ".")
}

Our respects from Perl devs too :))

func (ip IPAddr) String() string {
	return strings.Join(regexp.MustCompile("\\d+").FindAllString(fmt.Sprint([len(ip)]byte(ip)), -1), ".")
}

package main

import (
	"fmt"
	"strconv"
)

type IPAddr [4]byte

func (ip IPAddr) String() string {
	var str string
	for i, v := range ip {
		if convertedV := strconv.Itoa(int(v)); i == 0 {
			str += convertedV
		} else {
			str += "." + convertedV
		}
	}
	return str
}

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)
	}
}

Mine lol

package main

import "fmt"

type IPAddr [4]byte

// TODO: Add a "String() string" method to IPAddr.
func (ip_add IPAddr) String() string {
	return fmt.Sprintf("%d.%d.%d.%d", ip_add[0],ip_add[1],ip_add[2],ip_add[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)
	}
}

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\n", 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)
	}
}

package main

import "fmt"

type IPAddr [4]byte

func (ip IPAddr) String() string {
	return fmt.Sprintf("%d.%d.%d.%d", 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 _, ip := range hosts {
		fmt.Println(ip.String())
	}
}

Nice answer, I couldn't think of it

package main

import "fmt"

type IPAddr [4]byte

// TODO: Add a "String() string" method to IPAddr.
func (ip IPAddr) String() string {
	var ipFinal string = ""
	for i := range ip {
		if i < 3 {
			ipFinal = ipFinal + fmt.Sprintf("%d", ip[i]) + "."
		} else {
			ipFinal = ipFinal + fmt.Sprintf("%d", ip[i])
		}
	}
	return ipFinal
}

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)
	}
}

package main

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

type IPAddr [4]byte

// TODO: Add a "String() string" method to IPAddr.
func (ip IPAddr) String() string {
	s := make([]string, len(ip))
	for i, val := range ip {
		s[i] = strconv.Itoa(int(val))
	}
	return strings.Join(s, ".")
}

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)
	}
}

I'm using append instead of concat string

package main

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

type IPAddr [4]byte

func (ip IPAddr) String() string {
	s := make([]string, len(ip))
	
	for _, v := range ip {
		s = append(s, strconv.Itoa(int(v)))
	} 
	
	return strings.Join(s, ".")
}

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)
	}
}

I think it'd be better to declare the slice s like make([]string, 0, len(ip)). Otherwise, the output would be like "....127.0.0.1" as the append will add the digit from index 4.