string to float conversion?

Question

I\'m wondering what sort of algorithm could be used to take something like \"4.72\" into a float data type, equal to

float x = 4.72;

Answer 1

For C++ This is the algorithm I use:

bool FromString(const string& str, double& number) {

    std::istringstream i(str);

    if (!(i >> number)) {
        // Number conversion failed
        return false;
    }

    return true;
}

I used atof() in the past for the conversion, but I found this problematic because if no valid conversion can be made, it will return (0.0). So, you would not know if it failed and returned zero, or if the string actually had "0" in it.