英文:
How can i add extra digit to a BigDecimal?
问题
在下面的代码中，用户将输入firstAmount和secondAmount。然后程序将运行并进行如下计算：firstAmount*secondAmount/123，答案将保存在totalAmount变量中。接下来，程序将使用totalAmount进行一些额外的计算，但在此之前我想在totalAmount上添加额外的数字。例如，如果通过计算得到的totalAmount金额为23.021，那就可以了。但是，如果没有小数点，我希望添加它。例如，如果totalAmount得到了41，现在没有小数点，所以我想添加.00，这意味着totalAmount将变为41.00。我该怎么做？如何在没有小数点的情况下添加额外的数字？以下是我希望进行此操作的代码：
switch (spinner.getSelectedItemPosition()){
case 0: {
totalAmount = firstAmount.multiply(secondAmount).divide(new BigDecimal("123"), MathContext.DECIMAL128);
// 在进行下一次计算之前，如果totalAmount中没有小数点，我想添加额外的数字
if (totalAmount.scale() == 0) {
totalAmount = totalAmount.setScale(2); // 添加两位小数
}
nextCalculation = String.valueOf(totalAmount);
break;
}
}
英文:
In below code, user will enter firstAmount and secondAmount. Then program will run and do this calculation firstAmount*secondAmount/123 and answer will be in totalAmount variable. Further program will take the totalAmount and do some extra calculations, but before that i want to add extra digits to totalAmount. For example if by calculating totalAmount gets amount something like 23.021 that is okay. But it doesn't have any decimal point i would add that to it, for example if totalAmount gets amount 41 now there is no decimal point so i would add .00 means after that toalAmount will be 4.00. How do i do that ? How can i add extra digits if there is no already? Below is my code where i want this stuff to be happen.
switch (spinner.getSelectedItemPosition()){
case 0:
{
totalAmount = firstAmount.multiply(secondAmount).divide(new BigDecimal("123"), MathContext.DECIMAL128);
// before next calculation i want to add extra digits if there is no decimal point in the totalAmount
nextCalculation = String.valueOf(totalAmount);
break;
}
答案1
得分: 5
你可以始终在 BigDecimal 上使用 setScale(int newScale, RoundingMode roundingMode) 来增加小数位。请记住，BigDecimal 是不可变的。
if (totalAmount.scale() == 0) {
totalAmount = totalAmount.setScale(2, RoundingMode.UNNECESSARY);
}
英文:
You can always use setScale(int newScale, RoundingMode roundingMode) on BigDecimal to add decimal places. Remember BigDecimal is immutable.
if (totalAmount.scale() == 0) {
totalAmount = totalAmount.setScale(2, RoundingMode.UNNECESSARY);
}
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