Question

I am getting a string "4A4B4C4D4E4F".. it is equal to a string ("JKLMNO")

How can I check this type of string in c++.. (one string shows the hexadecimal representation of another)

hexadecimal value of

J=4A, K=4B, L=4C

Answer 1

Alternatively this can be done using C++ strings and features rather than C-style strings:

#include <iostream>
#include <sstream>
#include <iterator>
#include <algorithm>
#include <iomanip>
#include <string>

bool compareAscii(const std::string& string, const std::string& asciistr) {
   std::ostringstream result;
   result << std::setw(2) << std::setfill('0') << std::hex << std::uppercase;
   // We copy the contents of string, using the range from the beginning to the end.
   // By copying it to an ostream iterator it gets written to the ostringstream,
   // but crucially we treat it as an unsigned int when we write it, which causes
   // the chars to get printed as their numerical values instead.
   std::copy(string.begin(), string.end(), std::ostream_iterator<unsigned int>(result));
   return result.str() == asciistr;
}

namespace {
   const std::string test="JKLMNO";
   const std::string value="4A4B4C4D4E4F";
}

int main() {
   std::cout << "compareAscii(\"" << test << "\", \"" << value << "\") returned " << compareAscii(test, value) << std::endl;
   return 0;
}