How to convert to double with 2 precision - string

问题:

I want to convert this string: 0.55000000000000004 to this double: 0.55. How to do that?

回答1:

Is a string or a double? If it is a string:

double d = double.Parse(s,CultureInfo.InvariantCulture);
string s=string.Format("{0:0.00}",d);

if it is already a double just format using the second line.

回答2:

you can use this code to reduce precision part:

double m = Math.Round(0.55000000000000004,2);

Result would be : 0.55

回答3:

There is no double 0.55 - the number cannot be accurately represented as a binary fraction. Which is probably the reason why you got that long string in the first place. You should probably be using the decimal type instead of double.

Read The Floating-Point Guide to understand why.