DecimalFormat numform = new DecimalFormat("-0.00");
System.out.println( "Num = " + numform.format(-924.56) );

Answer:

Num = --924.56

Minus signs in the format pattern can be a problem.

Optional Format for Negative Numbers

The format pattern has an optional second half which shows how to treat negative numbers. The pattern looks like

positivePattern;negativePattern

A semicolon separates the two subpatterns. To avoid problems, make the pattern for the digits in positivePattern the same as in negativePattern. (This is not a formal rule, just good advice.) However, both patterns can contain additional characters on either side of the patterns for the digits. Put a space in the positivePattern where a negative sign appears in the negativePattern. For example

DecimalFormat numform = new DecimalFormat(" 00.00;-00.00"); 
System.out.println( "Pos = " + numform.format(12.6) );
System.out.println( "Neg = " + numform.format(-12.6) );

The positivePattern in this example starts with a space. The negativePattern starts with a minus sign. The program fragment outputs:

Pos =  12.60
Neg = -12.60

This is useful for writing out positive and negative numbers in columns with the decimal separators aligned. Here is the applet.

Embedded Java applet removed: modern browsers do not support Java applets. The surrounding source code is retained for historical study.

Try some patterns like 0.0;-0.0.

QUESTION 13:

What does the following fragment write?

double A= 24.8, B= -92.777, C= 0.009, D= -0.123;

DecimalFormat numform = new DecimalFormat(" 00.00;-00.00"); 

System.out.println( "A = " + numform.format(A) ); 
System.out.println( "B = " + numform.format(B) ); 
System.out.println( "C = " + numform.format(C) ); 
System.out.println( "D = " + numform.format(D) );

Copy and paste from the fragment into the applet to see the answers. But first work out the answer on your own.