Question

int ptstotal, ptsearned, ptssofar;
ptstotal= 1500;
ptsearned= 750;
ptssofar= 950;

System.out.println("The current percentage is "+(int)Math.round(ptsearned*1)/(double)(ptssofar)*100+"%.");

System.out.println("The current percentage is "+Math.round(ptsearned*1)/(double)ptssofar*100+"%.");

输出为长十进制78.96736805263％，只需要78.97％需要一些帮助

Answer 1

尝试使用printf

double value = (int)Math.round(ptsearned*1)/(double)(ptssofar)*100;
System.out.printf("The current percentage is %.2f %",value);

Answer 2

您可以使用DecimalFormat或formatted output与printf(String, Object...)一样

DecimalFormat df = new DecimalFormat("###.00");
System.out.println("The current percentage is "
        + df.format(Math.round(ptsearned * 1) / (double) (ptssofar)
                * 100) + "%.");
System.out.printf("The current percentage is %.2f%%.%n",
        Math.round(ptsearned * 1) / (double) ptssofar * 100);

哪些输出（请求的）

The current percentage is 78.95%.
The current percentage is 78.95%.

Answer 3

没有必要将数字乘以1，或者在您知道的整数数量上调用Math.round。保持简单。

double percentage = (double)ptsearned / ptssofar * 100;
System.out.format("The current percentage is %.2f%%%n", percentage);

在这里，您需要(double)来避免整数除法。然后，在格式字符串中，%.2f表示显示带有两个小数位的值。下一个%%将转换为百分号，最后%n转换为行分隔符。

我如何才能将其执行到两位小数，以十进制长的形式出现

3 个答案: