std::hex causes integers to be printed in hexadecimal representation. In order to revert back to hexadecimal representation, std::dec is used. //
// g++ hex.cpp
//
#include <iostream>
#include <iomanip>
int main() {
std::cout << 100 << std::endl;
std::cout << std::hex << 100 << std::endl;
std::cout << 100.1 << std::endl;
std::cout << std::dec << 100 << std::endl;
}
100 64 100.1 100
std::hex can also be used to convert a string that contains an integral value in hexadecimal represantion to a long: #include <iostream>
#include <sstream>
#include <string>
int main() {
std::stringstream ss;
std::string value_in_hex("1E240");
long value_in_dec;
ss << std::hex << "1E240";
ss >> value_in_dec;
std::cout << "0x" << value_in_hex << " = " << value_in_dec << std::endl;
}