java - 如何从字符串中删除尾随零？

Question

我有一个字符串salePrice，它可以有类似的值29.90000,91.01000，我想得到像29.90,91.01小数点后两位数一样的输出。我正在使用一个字符串。

Answer 1

可能的解决方案之一

new BigDecimal("29.90000").setScale(2).toString()

或者如果你需要四舍五入

new BigDecimal("29.90100").setScale(2, RoundingMode.HALF_UP).toString()

使用 BigDecimal 因为从 String 转换为 double 会丢失精度！

选择适合您情况的舍入模式。

Answer 2

尝试这个...

DecimalFormat df2 = new DecimalFormat( "#,###,###,###.##" );
double dd = 100.2397;
double dd2dec = new Double(df2.format(dd)).doubleValue();

Answer 3

int lastIndex = salePrice.indexOf(".") + 2
salePrice = salePrice.substring(0, lastIndex);

Answer 4

您可以使用

String.format("%.2f", value);

Answer 5

您可以使用Apache Commons 数学库

    NumberFormat nf = NumberFormat.getInstance();
    nf.setMinimumFractionDigits(2);
    nf.setMaximumFractionDigits(2);
    ComplexFormat cf = new ComplexFormat(nf);
    Complex complex = cf.parse("29.90000");

Answer 6

Here is an old-school way that matches your question (you always want 2 decimal places)

public class LearnTrim
{
    public static void main(final String[] arguments)
    {
        String value1 = "908.0100";
        String value2 = "876.1";
        String value3 = "101";
        String value4 = "75.75";
        String value5 = "31.";

        System.out.println(value1 + " => " + trimmy(value1));
        System.out.println(value2 + " => " + trimmy(value2));
        System.out.println(value3 + " => " + trimmy(value3));
        System.out.println(value4 + " => " + trimmy(value4));
        System.out.println(value5 + " => " + trimmy(value5));
    }

    private static String trimmy(final String value)
    {
        int decimalIndex;
        String returnValue;
        int valueLength = value.length(); // use StringUtils.length() for null safety.

        decimalIndex = value.indexOf('.');
        if (decimalIndex != -1)
        {
            if (decimalIndex < (valueLength - 3))
            {
                returnValue = value.substring(0, valueLength - 2);
            }
            else if (decimalIndex == (valueLength - 3))
            {
                returnValue = value;
            }
            else if (decimalIndex == (valueLength - 2))
            {
                returnValue = value + "0";
            }
            else // decimalIndex == valueLength - 1
            {
                returnValue = value + "00";
            }
        }
        else
        {
            returnValue = value + ".00";
        }

        return returnValue;
    }
}