Reading ASCII numbers using “D” instead of “E” for scientific notation using C

Question

I have a list of numbers which looks like this: 1.234D+1 or 1.234D-02. I want to read the file using C. The function atof will merely

Answer 1

Here this function is to replace "D" into "E" in the scientific notation with "D".

std::string dToE(string cppstr)
{
    str1.replace(cppstr.find("D"),1,"E");
    return cppstr;
}

If the C string for scientific notation is defined by: char * cstr = "1.2D+03"; or usually obtained by strtok method, which returns C string, then use atof(dToE(string(cstr)).c_str()) to get the scientific notation with "E".

Since atof only accept C style string, you should use c_str() string method to convert C++ string into C string.