为了赚钱，您应该在Java中使用哪种舍入方法？ [英] What rounding method should you use in Java for money?

问题描述

假设我在Java中有一个十进制值表示货币。

Suppose I have a decimal value in Java that represents money.

四舍五入这些值的最佳方法是什么？

What's the best way to round these values?

例如，如果我有一个基于税率计算的值，而最后得到的结果是税额 5.3999999999999995 ，我将其四舍五入到小数点后两位：

For example, if I have a value that's calculated based on a tax rate and I end up with a result of, say, 5.3999999999999995 as the tax amount, should I round it to 2 decimal places simply by doing this:

double d = 5.3999999999999995
BigDecimal bd = new BigDecimal(d).setScale(2, RoundingMode.HALF_EVEN);
d = bd.doubleValue();

产生货币值：

5.40

推荐答案

最多计算货币的应用程序不使用浮点数（ double ， float ）；他们使用代表较小单位的整数。例如，在$ USD中，货币可以用 pennies 表示，即1美元的1/100。

Most applications that calculate money don't use floating point (double, float); they use integer amounts representing a smaller unit. For example in $USD, money can be represented in pennies which is 1/100 of a dollar.

为获得更好的准确性，您可能希望使用代表1E-03（毫安美元）或1E-06的整数。这取决于诸如利息计算和您的精确度等问题。

For better accuracy, you may want to have an integer represent 1E-03 ("milli-dollars") or 1E-06. This depends on issues such as interest calculations and your level of precision.

这篇关于为了赚钱，您应该在Java中使用哪种舍入方法？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！