数值格式问题

Question

DecimalFormat format = new DecimalFormat("####.##");
double data = 123.12345678;
String doubleFormat = format.format(data);
data = Double.parseDouble(doubleFormat);

Answer 1

DecimalFormat nf = new DecimalFormat("##0.##");
        System.out.println(nf.format(1254.56789));
        System.out.println(nf.format(1254));
        System.out.println(nf.format(.56789));
        System.out.println(nf.format(0));
output:1254.57
1254
0.57
正负转化? a *= -1;
0

Answer 2

DecimalFormat nf = new DecimalFormat("##0.00");