Java大双精度损失

Question

 double lnumber = Math.pow(2, 1000);

版画 1.0715086071862673E301

我尝试过的事情

我试图通过使用BigDecimal类扩展此数字:

 String strNumber = new BigDecimal(Double.toString(lnumber)).toPlainString();

这只是打印:

10715086071862673000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

我也尝试过使用DecimalFormat:

    DecimalFormat df = new DecimalFormat("#");
    df.setMaximumFractionDigits(0);
    String strNumber = String.valueOf(df.format(lnumber));

打印相同的东西:

10715086071862673000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

根据Wolfram Alpha的实际答案是

如何打印所有实际值？

Answer 1

你不能混合和匹配Math,原始类型和BigDecimal,如果你想要真正的精度,只需使用BigDecimal:

BigDecimal value = new BigDecimal(2);
System.out.println(value.pow(1000));