how to calculate subnet mask

This article describes how to verify the validity of IP addresses and subnet masks in js. For more information, see The Code is as follows: Function checkIP){Obj = ip;Var exp =/^ (\ d {1, 2} | 1 \ d | 2 [0-4] \ d | 25 [0-5]) \. (\ d {1, 2} | 1 \ d | 2 [0-4] \ d | 25 [0-5]) \. (\ d {1, 2} | 1 \ d | 2 [0-4] \ d | 25 [0-5]) \. (\ d {1, 2} | 1 \ d | 2 [0-4] \ d | 25 [0-5]) $ /;Var reg = obj. match (exp );If (reg = null){Return false; // invalid}Else

)); System.out.println (Inttoip (Dhcpinfo.gateway)); System.out.println (Inttoip (dhcpinfo.serveraddress)); System.out.println (Inttoip (dhcpinfo.dns1)); System.out.println (Inttoip (DHCPINFO.DNS2)); System.out.println (dhcpinfo.leaseduration); Sb.append ("WiFi info:"); Sb.append ("\nipaddress:" + Inttoip ( Wifiinfo.getipaddress ())); Sb.append ("\nmacaddress:" + wifiinfo.getmacaddress ()); Tvresult.settext (sb.toString ());} Private String Inttoip (int paramint) {return (Paramint 0xFF) + "." +

How to calculate the subnet ID of an IP address correctly?From:How to calculate the correct subnet for a interface (document ID 1059759.1)Suitable for:Oracle database-enterprise edition-version 10.2.0.1 and laterInformation in this document applies to any platform.Goal:The subnet