Day_16_ValidateIPAddress.java

class Solution {
  public static String validIPAddress(String IP) {
        String[] ipv4 = IP.split("\\.",-1);
        String[] ipv6 = IP.split("\\:",-1);
      
        if(ipv4.length==4){
            for(String s : ipv4) {
                if(isIPv4(s)) continue;
                else return "Neither"; 
            }
             return "IPv4";
        }
        if(ipv6.length==8){
            for(String s : ipv6) {
                if(isIPv6(s)) continue;
                else  return "Neither";
            }
            return "IPv6";
        }
      
        return "Neither";
    }
    
    public static boolean isIPv4 (String s){
         try{ 
             
             return String.valueOf(Integer.valueOf(s)).equals(s) && 
                 Integer.parseInt(s) >= 0 &&
                 Integer.parseInt(s) <= 255;
         }
         catch (NumberFormatException e){
             return false;
         }
    }
    
    public static boolean isIPv6 (String s){
        
        if (s.length() > 4 ) return false;
        try {
            return Integer.parseInt(s, 16) >= 0 && s.charAt(0)!='-';
        }
        catch (NumberFormatException e){
            return false;
        }
    }
}