determines if a string is a valid IPv4 address in golang, but the correct way to do this is to use net.ParseIP() and check for err

is_ipv4.go

package main

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

func is_ipv4(host string) bool {
	parts := strings.Split(host, ".")

	if len(parts) < 4 {
		return false
	}
	
	for _,x := range parts {
		if i, err := strconv.Atoi(x); err == nil {
			if i < 0 || i > 255 {
			return false
		}
		} else {
			return false
		}

	}
	return true
}

func main() {
	addresses := []string{"192.168.1.1", "10.addr.3.4"}

	for _, address := range addresses {

		if is_ipv4(address) {
			fmt.Println("This is a valid IPv4 address")
			continue
		}
		fmt.Println("This is NOT a valid IPv4 address")
	}
}