How to "append" significant figures to double from float value

Question

Currently I am trying to match a C# and C++ application. On the C++ side, when there is a value, say:

const char* svalue = "554.1327";

When I use sscanf:

float x;
sscanf(svalue, "%f", &x);

x will equate to 554.13269, i.e. it has "additional" significant figures, even though they may round to the same value. (I think this application uses a different float type which can hold more than 7 significant figures.)

I do not want to change the C++ side. I would like my seperate C# appliaction to do the same.

For example, if I have the float 23423.29, I would like to convert it to 23423.289, which is a double (since in C#, standard float has no more than 7 significant figures), then convert that double into a string.

I cannot seem to find a method to do this. Any ideas? Or do I have to create my own function or call into the same C++ function from the C# side…?

Answer 1

Hi there is a temprary solution for your problem like

            Double d = 23423.29f;
        int a = 23423.29.ToString().Length;
        Console.WriteLine(d.ToString().Remove(++a));

which gives result

23423.289