EvilZone

Programming and Scripting => Java => Topic started by: Super_mario666 on March 15, 2013, 07:34:18 PM

Title: Illegal Format Conversion Exception
Post by: Super_mario666 on March 15, 2013, 07:34:18 PM

im having a problem while try to output data to a file. it keeps throwing "java.util.IllegalFormatConversionException"


this the part with the problem

Code: (java) [Select]

           try{

            out = new Formatter("allaccounts.txt");
            }
            catch(FileNotFoundException ex){
                System.err.println("Error: File not Found!");
                System.exit(1);
                return;
            }



            for(int i = 0; i < start.getnumAcc();i++)
      {
         
         outs.format("%d ",users[i].getNum());   
         outs.format("%s ",users[i].getName());
         outs.format("%s ",users[i].getPass());   
         outs.format("%d\n",users[i].getBalan()); //returns double- line that throws the exception
      }


      outs.close();




when i googled it i found out it  the %d should be a %f. but when i do that the data gets written all wrong.

for example, if users.getBalan() returns 123.45 it would be instead write 123.450000 to it.

Title: Re: Illegal Format Conversion Exception
Post by: Kulverstukas on March 15, 2013, 08:51:54 PM

You can't cast a float to an int. So output a float, and you can control how many numbers should be after the dot by doing:
%.Nf
Where N is a number, example: %.2f, would give you 123.45

Title: Re: Illegal Format Conversion Exception
Post by: Deque on March 15, 2013, 09:04:56 PM

This should answer your questions: (from http://docs.oracle.com/javase/1.5.0/docs/api/java/util/Formatter.html#syntax)

Quote 'd' integral The result is formatted as a decimal integer

Quote

Integral - may be applied to Java integral types: byte, Byte, short, Short, int and Integer, long, Long, and BigInteger

Quote

The number of digits in the result for the fractional part of m or a is equal to the precision.  If the precision is not specified then the default value is 6. If the precision is less than the number of digits which would appear after the decimal point in the string returned by Float.toString(float) or Double.toString(double) respectively, then the value will be rounded using the round half up algorithm (http://docs.oracle.com/javase/1.5.0/docs/api/java/math/BigDecimal.html#ROUND_HALF_UP).  Otherwise, zeros may be appended to reach the precision. For a canonical representation of the value,use Float.toString(float) or Double.toString(double) as appropriate.