Java Help!!

[DaveNY]

Hi I wrote code for Java program to simulate the rolling of 2 dice. The application should roll the dice 36,000 times. In a tabular format it should show the frequency of rolling 2,3,4,5,6,7,8,9,10,11,12 and also the percentage. It compiles alright but I am not getting the output. Can someone help me find out why I am not getting the output. Thank you for your help. Here is the code:

// Program simulates rolling two six-sided dice 36,000 times.
import java.util.Random;
public class Roll36
{
   // simulate rolling of dice 36000 times
   public void rollDice()
   {
      Random randomNumbers = new Random();
      int face1; // number on first die
      int face2; // number on second die
      int totals[] = new int[ 13 ]; // frequencies of the sums
      // initialize totals to zero
      for ( int index = 0; index < totals.length; index++ )
         totals[ index ] = 0;
      // roll the dice
      for ( int roll = 1; roll <= 36000; roll++ ) {
         face1 = 1 + randomNumbers.nextInt( 6 );
         face2 = 1 + randomNumbers.nextInt( 6 );
         totals[ face1 + face2 ]++;
      } // end for
      // print the table
      System.out.printf( "%3s%12s%12s\n",
         "Sum", "Frequency", "Percentage" );
      // ignore subscripts 0 and 1
      for ( int k = 2; k < totals.length; k++ )
      {
         double percent = ( double )totals[ k ] / 36000 * 100;
         System.out.printf( "%3d%12d%12.2f\n", k, totals[ k ], percent );
      } // end for
   } // end method rollDice
} // end class Roll36

[Dukane]

You do not have a main method! I added the main method declaration and now it works just fine!

[qkerby]

// Program simulates rolling two six-sided dice 36,000 times.
import java.util.Random;
public class Roll36
{
   public static void main(String[] args){
      Roll36 roller = new Roll36();
      //I'd pass the 36000 into the rollDice method as an argument
      //Or better yet, do the for loop in main and 
      //Have the rollDice method do nothing but roll the dice and return 
      //result
      roller.rollDice(36000);
   }
   // simulate rolling of dice 36000 times
   public void rollDice(int rolls)
   {
      Random randomNumbers = new Random();
      int face1; // number on first die
      int face2; // number on second die
      int totals[] = new int[ 13 ]; // frequencies of the sums
      // initialize totals to zero
      for ( int index = 0; index < totals.length; index++ )
         totals[ index ] = 0;
      // roll the dice
      for ( int roll = 1; roll <= rolls; roll++ ) {
         face1 = 1 + randomNumbers.nextInt( 6 );
         face2 = 1 + randomNumbers.nextInt( 6 );
         totals[ face1 + face2 ]++;
      } // end for
      // print the table
      //It's common in java to use println rather than printf
      System.out.println( "%3s%12s%12s\n",
         "Sum", "Frequency", "Percentage" );
      // ignore subscripts 0 and 1
      for ( int k = 2; k < totals.length; k++ )
      {
         double percent = ( double )totals[ k ] / rolls * 100;
         //I don't think this is going to print what you think
         System.out.println( "%3d%12d%12.2f\n", k, totals[ k ], percent );
      } // end for
   } // end method rollDice
} // end class Roll36

[qkerby]

Oh, and if you are going to program in Java... please, please put your classes in a package. And don't get out of that habit.

package test.daveny;
//Now the imports