Search code examples
c++mathtype-conversionscientific-notation

String in scientific notation C++ to double conversion

I've got a database filled up with doubles like the following one: 

1.60000000000000000000000000000000000e+01

Does anybody know how to convert a number like that to a double in C++?

Is there a "standard" way to do this type of things? Or do I have to roll my own function?

Right now I'm doing sth like this:

#include <string>
#include <sstream>



int main() {
    std::string s("1.60000000000000000000000000000000000e+01");
    std::istringstream iss(s);
    double d;
    iss >> d;
    d += 10.303030;
    std::cout << d << std::endl;
}

Thanks!

Solution

  • Something like this? This would be the "C++" way of doing it...

    #include <sstream>
using namespace std;

// ...

    string s = "1.60000000000000000000000000000000000e+01";
    istringstream os(s);
    double d;
    os >> d;
    cout << d << endl;

    Prints 16.