Illegal format conversion exception for printf

[Ben Hultin]

I am trying to get this printf to work for displaying double variables that have been cast typed to int. I am not really sure what to do here.

    

// printf formating variables
	String HEADING_FMT_STR = "%10s%10s%10s%10s%10s%10s\n";
	String DATA_FMT_STR = "%10d,%10d,%10d,%10d,%10d,%10d,\n";




// performs random assignment of each roll
					dieOne = min + (int) (Math.random() * (max - min + 1));
					dieTwo = min + (int) (Math.random() * (max - min + 1));
					dieThree = min + (int) (Math.random() * (max - min + 1));
					dieFour = min + (int) (Math.random() * (max - min + 1));
					dieFive = min + (int) (Math.random() * (max - min + 1));
					dieSix = min + (int) (Math.random() * (max - min + 1));
				
					// displays result of random rolls into a table format
					System.out.printf(HEADING_FMT_STR, "First", "Second", "Third", "Fourth", "Fith", "Sixth");
					System.out.printf(HEADING_FMT_STR, "-----", "------", "-----", "------", "----", "-----");
					System.out.printf(DATA_FMT_STR, dieOne, dieTwo, dieThree, dieFour, dieFive, dieSix);

Here is the error report I got when compiling the code:

First Second Third Fourth Fith Sixth
----- ------ ----- ------ ---- -----
Exception in thread "main" java.util.IllegalFormatConversionException: d != java
.lang.Double
at java.util.Formatter$FormatSpecifier.failConversion(Unknown Source)
at java.util.Formatter$FormatSpecifier.printInteger(Unknown Source)
at java.util.Formatter$FormatSpecifier.print(Unknown Source)
at java.util.Formatter.format(Unknown Source)
at java.io.PrintStream.format(Unknown Source)
at java.io.PrintStream.printf(Unknown Source)
at GreedGame.main(GreedGame.java:152)

[fred rosenberger]

Which is line 152?

[Ben Hultin]

sorry about that, line 152 is:

 
System.out.printf(DATA_FMT_STR, dieOne, dieTwo, dieThree, dieFour, dieFive, dieSix); 

  

would i need to set DATA_FMT_STR to an int or double for it work?

[Campbell Ritchie]

What form are the variables to be printed? You would appear to be passing doubles tothe %d tag which expects an integer. Is min an int or a double?

[Ben Hultin]

Thanks a lot for pointing that out, rather obvious I must admit looking at it. So I am no longer getting an error, but now I am getting a floating point result, as to be expected. How could I convert the double variables to produce an int result for the printf method?

This is what I am getting now.

Please roll your die ("roll" or "end_turn"): roll
First Second Third Fourth Fith Sixth
----- ------ ----- ------ ---- -----
4.000000 2.000000 3.000000 4.000000 1.000000 4.000000

Thanks a lot for your help

[Campbell Ritchie]

You want integer result from a die, so you want its variables in integer format. Declare min as an int.

[Ben Hultin]

well min and max are declared as ints already. I believe the problem lies in the fact that dieOne through dieSix are double and need to be double bc:

    
        dieOne = min + (int) (Math.random() * (max - min + 1));
	dieTwo = min + (int) (Math.random() * (max - min + 1));
	dieThree = min + (int) (Math.random() * (max - min + 1));
	dieFour = min + (int) (Math.random() * (max - min + 1));
	dieFive = min + (int) (Math.random() * (max - min + 1));
	dieSix = min + (int) (Math.random() * (max - min + 1));

require a double variable (atleast that what my book tells me with regards to Math.random() methods, that and I stoped getting errors when I declared them doubles then cast typed them to int.

As before I tried using the %d formatter which I found didnt work because it found double variables not int. So now I am wondering if I should create int variables to assign the value from the double variables to it and result an int value to be printed. Does that sound like a good idea?

[Campbell Ritchie]

Yes, dieOne, dieTwo, etc should be ints because the results of dice are always whole numbers.

[Campbell Ritchie]

And I presume you haven't leanred about arrays yet.

[Ben Hultin]

Ok so I went and did a cast type to convert from double to int, compiler didnt complain about that.

  

// performs random assignment of each roll
					dieOne = min + (int) (Math.random() * (max - min + 1));
					dieTwo = min + (int) (Math.random() * (max - min + 1));
					dieThree = min + (int) (Math.random() * (max - min + 1));
					dieFour = min + (int) (Math.random() * (max - min + 1));
					dieFive = min + (int) (Math.random() * (max - min + 1));
					dieSix = min + (int) (Math.random() * (max - min + 1));
					
					// converts dieOne through dieSix from double to int
					int dieOneInt = (int) dieOne;
					int dieTwoInt = (int) dieTwo;
					int dieThreeInt = (int) dieThree;
					int dieFourInt = (int) dieFour;
					int dieFiveInt = (int) dieFive;
					int dieSixInt = (int) dieSix;
				
					// displays result of random rolls into a table format
					System.out.printf(HEADING_FMT_STR, "First", "Second", "Third", "Fourth", "Fith", "Sixth");
					System.out.printf(HEADING_FMT_STR, "-----", "------", "-----", "------", "----", "-----");
					System.out.printf(DATA_FMT_STR, dieOneInt dieTwoInt dieThreeInt dieFourInt dieFiveInt dieSixInt);

 

These are the changes I have made. The errors I am getting now are the ones below. To note I did change:

   
String DATA_FMT_STR = "%10d,%10d,%10d,%10d,%10d,%10d,\n";
 

from %10f to %10d for integers

GreedGame.java:160: ')' expected
System.out.printf(DATA_FMT_STR, dieOneIn
t dieTwoInt dieThreeInt dieFourInt dieFiveInt dieSixInt);
^ (carrot should be just under begin of dieTwoInt)

GreedGame.java:160: ';' expected
System.out.printf(DATA_FMT_STR, dieOneIn
t dieTwoInt dieThreeInt dieFourInt dieFiveInt dieSixInt);
^ (carrot should be just under begin of dieFiveInt)
GreedGame.java:160: ';' expected
System.out.printf(DATA_FMT_STR, dieOneIn
t dieTwoInt dieThreeInt dieFourInt dieFiveInt dieSixInt);
^ (carrot should just under last ')' )
3 errors

I appreciate any help in the matter

[W. Joe Smith]

Not sure, but here

  System.out.printf(DATA_FMT_STR, dieOneInt dieTwoInt dieThreeInt dieFourInt dieFiveInt dieSixInt);  

Are you supposed to seperate each of those with a comma? This is the only code that wasn't like dieOneInt, dieTwoInt, dieThreeInt, etc.

[Ben Hultin]

Thanks a lot for all your help, the commas did seem to be the problem, I added the commas in the printf and removed the commas in the DATA_FMT_STR. Now it is working properly.