"printf" applied to a float using a Parameter

[Wolfgang Obi]

Hi ,
i would please like to know if it is possible to replace the "2" (bold/italicised - see below) with a variable for example "afterKomma"?...if yes, how do i implement this, if no, what other (better?) options do i have ?

public void printFloat(){
   int afterKomma;
     double floatValue = 1234.5678;
 
       System.out.printf( "%.[I][B]2[/B][/I]f\n", floatValue);
}

what i'm asking basically is how can i realise something like this:

 System.out.printf( "%[B]--afterKomma--[/B]f\n", floatValue);

thanks
[ June 18, 2006: Message edited by: Wolfgang Obi ]

[Campbell Ritchie]

I trust you have been through the API specifications about the % tags? Look in the java.util.Formatter class. Then tell us how you sorted out the problem.

[Campbell Ritchie]

. . . and for variable numbers after the decimal point . . .

Difficult

. . .

You will have to go to the NumberFormat or DecimalFormat classes and see whether you can find any methods which allow you to set digits in the fraction.

There is a silly example on this website from another German chap. Look at it.

[Wolfgang Obi]

Hey Ritchie,

thanks once again for all the help and prodding in the right direction ...
here's how i finally solved the problem:

   public void printFloat(Rational bruch1){
   int numer = bruch1.getNumer();
   int denom = bruch1.getDenom();
   int afterKoma = 1;
 
      double floatValue1 = (float)  (numer);
      double floatValue2 = (float)  (denom);
      double theFloatValue = floatValue1/floatValue2;
 
 
    System.out.println
    ("how many positions after the decimal point?");
    System.out.println();
    afterKoma = IM.readInt();
 
   NumberFormat converter = NumberFormat.getInstance() ;
   converter.setMaximumFractionDigits(afterKoma);
   converter.setMinimumFractionDigits(afterKoma);
   System.out.print
        ("your Float Value is:  "+converter.format(theFloatValue));
   System.out.println();
 
}

[ June 18, 2006: Message edited by: Wolfgang Obi ]

[Campbell Ritchie]

Glad to be able to help

[Jesper de Jong]

Another way you could have solved this:

Note that the string "%.2f\n" is just a String object. It does not have to be a literal string; you can pass any other String object instead.

int afterKomma = 4;
System.out.printf( "%." + afterKomma + "f\n", floatValue);

[Wolfgang Obi]

thanks jasper.
looks less complicated :-)

cheers-

-W.O.

[Campbell Ritchie]

Another way you could have solved this:

I wish I had thought of that
Quite right.