Format Number in Java

Formatting number is something that u might always require in scenarios like, when you are trying to create a sequence number or a unique ticket number, math calculations that would require scientific notations etc. Every technology would have a provision for this. The one found is java is sophisticated.

// The 0 symbol shows a digit or 0 if no digit present

NumberFormat formatter = new DecimalFormat("000000");

String s = formatter.format(-1234.567);  // -001235

// notice that the number was rounded up

// The # symbol shows a digit or nothing if no digit present

formatter = new DecimalFormat("##");

s = formatter.format(-1234.567);         // -1235

s = formatter.format(0);                 // 0

formatter = new DecimalFormat("##00");

s = formatter.format(0);                 // 00

// The . symbol indicates the decimal point

formatter = new DecimalFormat(".00");

s = formatter.format(-.567);             // -.57

formatter = new DecimalFormat("0.00");

s = formatter.format(-.567);             // -0.57

formatter = new DecimalFormat("#.#");

s = formatter.format(-1234.567);         // -1234.6

formatter = new DecimalFormat("#.######");

s = formatter.format(-1234.567);         // -1234.567

formatter = new DecimalFormat(".######");

s = formatter.format(-1234.567);         // -1234.567

formatter = new DecimalFormat("#.000000");

s = formatter.format(-1234.567);         // -1234.567000

// The , symbol is used to group numbers

formatter = new DecimalFormat("#,###,###");

s = formatter.format(-1234.567);         // -1,235

s = formatter.format(-1234567.890);      // -1,234,568

// The ; symbol is used to specify an alternate pattern for negative values

formatter = new DecimalFormat("#;(#)");

s = formatter.format(-1234.567);         // (1235)

// The ' symbol is used to quote literal symbols

formatter = new DecimalFormat("'#'#");

s = formatter.format(-1234.567);         // -#1235

formatter = new DecimalFormat("'abc'#");

s = formatter.format(-1234.567);         // -abc1235

String pre=”xx”;

String post=”yy”;

formatter = new DecimalFormat(pre+"'abc'000000"+post);

s=formatter.format(12.3);           // xxabc000012yy

In addition to this you can also print formatted output ot the console by using System.out.format command

System.out.format("%5s", Integer.toString(n));  //     n  (- including 5 white spaces)

Hope this helps J