java - 如何在java中四舍五入？

Question

我试图在最后一位四舍五入显示一个浮点数，例如：0.123455 将显示为 0.12346，0.123454 将显示为 0.12345。我当前的代码（不能正常工作）如下：

int iFactorSum = 100000;
            int iRoundSum = (int) (fSumatoria * iFactorSum + 0.5);
            fSumatoria = (float) iRoundSum / iFactorSum;

fSumatoria 存储我要转换的数字。谢谢

Answer 1

To round up, you can use Math.ceil(numberGrade).

To round to the nearest integer, use Math.round(numberGrade).

See: the Math class

From here.

Answer 2

用于Math.round()四舍五入浮点数

见 https://docs.oracle.com/javase/7/docs/api/java/lang/Math.html#round(double)