snowbug wrote:
Please specify what exactly you want with the width of the output.

lucky_sesame wrote:
我刚来,还没有积分,这么多好书都下载不了,我哭....呜... 呜...呜

        DecimalFormat df = new DecimalFormat("$000,000.0000");
        String s = df.format(1234.329);  //$001, 234.3290
        String s2 = df.format(39185129835.31); //$39, 185, 129, 835.3100

mitnickcbc wrote:
谢谢！
唉，没想到java这方面这么弱。

floater wrote:
Actually, it's quite powerful now, :).

import java.text.DecimalFormat;

public class Formatter
{
    public static void main(String[] args)
    {
        //format double
        double a = 12314958.123548d;
        DecimalFormat df = new DecimalFormat("#0.000");
        System.out.println("a=" + df.format(a));

        //format string
        String format1 = "0000000000";
        System.out.println("10 digits with prepending 0's = [" + leftAppend(format1, "1234") + "]");
        String format2 = "          ";
        System.out.println("10 alphanum with prepending spaces = [" + leftAppend(format2, "abc") + "]");
    }

    /**
     * @param format The "background"
     * @param s format target
     * @return formatted or unchanged if s is larger than format
     */
    public static String leftAppend(String format, String s)
    {
        if (s.length()<format.length())
        {
            return format.substring(s.length()) + s;
        }
        return s;
    }
}