Validate IP Address in C++

C++Server Side ProgrammingProgramming

This article is serving the purpose of validating the correct IP (internet protocol) address by virtue of C++ code programming. The IP address is a 32-bit dot-decimal-notation, broken into four decimal numbers segments ranging from 0 to 255. Furthermore, these numbers are separated by dots consecutively. The IP address serves the purpose of identifying a host machine in the network in a unique manner in order to establish a connection among them.

So, in order to validate the correct IP address input from the user-end, the following algorithm briefs how exactly the code sequence is materialized to identify the correct IP address as follows;


   Step-1: Input the IP address
   Step-2: Spilt the IP into four segments and store in an array
   Step-3: Check whether it numeric or not using
   Step-4: Traverse the array list using foreach loop
   Step-5: Check its range (below 256) and data format
   Step-6: Call the validate method in the Main()

Thence, as per the algorithm the following c++ drafted to validate the IP address, in which couple of essentials functions are being employed to determine the numeric form, range, and splitting the input data respectively;


 Live Demo

#include <iostream>
#include <vector>
#include <string>
using namespace std;
// check if the given string is a numeric string or not
bool chkNumber(const string& str){
   return !str.empty() &&
   (str.find_first_not_of("[0123456789]") == std::string::npos);
// Function to split string str using given delimiter
vector<string> split(const string& str, char delim){
   auto i = 0;
   vector<string> list;
   auto pos = str.find(delim);
   while (pos != string::npos){
      list.push_back(str.substr(i, pos - i));
      i = ++pos;
      pos = str.find(delim, pos);
   list.push_back(str.substr(i, str.length()));
   return list;
// Function to validate an IP address
bool validateIP(string ip){
   // split the string into tokens
   vector<string> slist = split(ip, '.');
   // if token size is not equal to four
   if (slist.size() != 4)
      return false;
   for (string str : slist){
      // check that string is number, positive, and range
      if (!chkNumber(str) || stoi(str) < 0 || stoi(str) > 255)
         return false;
   return true;
   // Validate an IP address in C++
int main(){
   cout<<"Enter the IP Address::";
   string ip;
   if (validateIP(ip))
      cout <<endl<< "***It is a Valid IP Address***";
      cout <<endl<< "***Invalid IP Address***";
   return 0;

After the compilation of the above code using a standard c++ editor, the following output is being produced which is duly checking whether the input number is a correct IP address or not as follows;


Enter the IP Address::
***It is a Valid IP Assress***
Updated on 29-Nov-2019 11:08:26