go对字符的迭代

package main

import (
   "fmt"
   "strings"
)

func main() {
   ip:="192.168.0.10"
i:=0
str:="osdf"
for _,c:=range str{
      i++
      if c == 'l'{
         break
}

   }
   fmt.Println(i)
   ips:=strings.Split(ip,".")
   for _,v:=range ips{
      if v == ""{
         return
}
      if len(v) >1 &&v[0]==0 {
         return
}
   }

}

func IsIpv4(ip string) bool {
	//matched, _ := regexp.MatchString("((2(5[0-5]|[0-4]\\d))|[0-1]?\\d{1,2})(\\.((2(5[0-5]|[0-4]\\d))|[0-1]?\\d{1,2})){3}", ip)
	arr := strings.Split(ip, ".")
	if len(arr) != 4 {
	return false
	}
	for _, v := range arr {
	if v == "" {
	return false
	}
	if len(v) > 1 && v[0] == '0' {
	return false
	}
	num := 0
	for _, c := range v {
	if c >= '0' && c <= '9' {
	num = num*10 + int(c-'0')
	} else {
	return false
	}
	}
	if num > 255 {
	return false
	}
	}
	return true
	}