java中如何计算百分比之后保留指定…

double passPercent=pass/(double)score.length;

double excellentPercent=excellent/(double)score.length;

//获取格式化对象

NumberFormat nt=NumberFormat.getPercentInstance();

nt.setMinimumFractionDigits(2);

System.out.println("及格率为："+nt.format(passPercent));

System.out.println("优秀率为："+nt.format(excellentPercent));