how to convert a character into integer in c++ code example

Example 1: char to int c++

int x = (int)character - 48;

Example 2: char* to int in cpp

int x = std::stoi("42")

Example 3: converting char to int in c++

#include <sstream>

using namespace std;

int main()
{
    stringstream str;
    
    str << "1";

    double x;
    str >> x;
}