如何将浮点数向上舍入到 C# 中最近的整数？

Question

In C#, how do I round a float upwards to the nearest int?

I see Math.Ceiling and Math.Round, but these returns a decimal. Do I use one of these then cast to an Int?

Answer 1

If you want to round to the nearest int:

int rounded = (int)Math.Round(precise, 0);

You can also use:

int rounded = Convert.ToInt32(precise);

Which will use Math.Round(x, 0); to round and cast for you. It looks neater but is slightly less clear IMO.

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If you want to round up :

int roundedUp = (int)Math.Ceiling(precise);

Answer 2

Off the top of my head:

float fl = 0.678;
int rounded_f = (int)(fl+0.5f);

Answer 3

(int)Math.Round(myNumber, 0)

Answer 4

最简单的方法是向其添加0.5f ，然后将其转换为 int。

Answer 5

Do I use one of these then cast to an Int?

Yes. There is no problem doing that. Decimals and doubles can represent integers exactly, so there will be no representation error. (You won't get a case, for instance, where Round returns 4.999... instead of 5.)

Answer 6

您可以转换为 int，前提是您确定它在 int 的范围内（Int32.MinValue 到 Int32.MaxValue）。