Need to return a *char not address of...

[Cheezewizz]

First of all I'd just do std::cout << cNum << std::endl; rather than passing a pointer to it...... but then there's also one or two things that could also do with changing before it works properly. Like sockman mentioned, you shouldn't be returning a pointer to something declared locally in the function. I'd change what you have to something more like this....

#include <cstdio>
#include <iostream>

const char *ftostr(float dVar, char* buffer)
{
   // char ans[20];

    snprintf(buffer, 20, "%f", dVar);

    return buffer;
}

int main()
{
    double fNum;// = 3.145;
    std::cout << "Enter a decimal value: ";
    std::cin >> fNum;
    char buffer[20];
    //const char *cNum = ftostr(fNum);
    ftostr(fNum, buffer);
    
    std::cout << buffer << std::endl;
    
    system("pause");
    
    return 0;    
}