Format a number with leading sign

April 24, 2023 by Tarik

Use a negative subpattern, as described in the javadoc for DecimalFormat.

DecimalFormat fmt = new DecimalFormat("+#,##0.00;-#");
System.out.println(fmt.format(98787654.897));
System.out.println(fmt.format(-98787654.897));

produces (in my French locale where space is the grouping separator and the comma is the decimal separator) :

+98 787 654,90
-98 787 654,90