Prevent rounding off in string.format

Question

string xyz = "23.659";
return string.Format("{0:F"+2+"}", xyz);

output = 23.66

When I use string.format the value gets rounded off, but I need 23.65 as the output. How to prevent rounding off in string.format?

Answer 1

You can round the value manually, e.g. with a help of Math.Round:

// If you have string (not decimal or double) we'll have parse
string xyz = "23.659";

return double.TryParse(xyz, out var value)
  ? string.Format("{0:F2}", Math.Round(value, 2, MidpointRounding.ToZero))
  : xyz;

If xyz is of type float, double, decimal which is more natural the code doesn't want parsing:

double xyz = 23.659;

return string.Format("{0:F2}", Math.Round(xyz, 2, MidpointRounding.ToZero));