double f = 1314.135645(以保留其小数点后两位为例) 方法一: public void m1( ) { BigDecimal bg = new BigDecimal(f); Double f1 = bg.setScale(2,BigDecimal.ROUND_HALF_UP).doubleValue( ); System.out.println(f1);
} 方法二:DecimalFormat转换最简便 public void m2( ) { DecimalFormat df = new DecimalFormat("#.00"); System.out.println(df.format(f));
}
方法三:String.format打印最简便 public void m3( ) { System.out.println(String.format("%.2f", f)); } 方法四: public void m4( ) { NumberFormat nf = NumberFormat.getNumberInstance( ); nf.setMaximumFractionDigits(2); System.out.println(nf.format(f));
}
输出答案为:
1314.14
1314.14
1314.14
1,314.14