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nvibest
09-17-2008, 09:48 PM
Hello,
I recently have been trying to write a simple program that involves the use of arrays and a random number generator in order to simulate rolling a six sided fair die.
I've posted my coding so far below...


import java.util.Random;
public class RollDie {
public static void main(String[] args) {
//Create an array of ints to hold the results of 5 rolls of a
//die.

int [] array = {1, 2, 3, 4, 5, 6};


//Create a Random object to generate random values
Random generator = new Random ();

//Use the Random object to place a random value between 1 and 6
//in each position of the array to hold the result of each roll

array[1] = generator.nextInt(6) + 1;
array[2] = generator.nextInt(6) + 1;
array[3] = generator.nextInt(6) + 1;
array[4] = generator.nextInt(6) + 1;
array[5] = generator.nextInt(6) + 1;


//Display the results of the five rolls

System.out.println ("Five rolls of a die: " + (array[1]) + " " + (array[2]) + " " + (array[3]) + " " + (array[4]) + " " + (array[5]) );

//Use the Random object to randomly select two of the five rolls
//(sometimes, one die may be selected twice-that's OK)

System.out.println ("Die 1 (from roll " + "2): "+ 5);

//Display the rolls selected and their sum as illustrated below.


}

}


I've been able to write it successfully up until the part where I need to take the 5, just rolled die, and randomly pick 2 of the roles to display in the format above.....e.i.' System.out.println ("Die 1 (insert first randomly picked die), //then on the second line.."Die 2 (insert second randomly picked die))....

As you can see I'm having some trouble figuring out how to randomly pick 2 out of the 5 arrays I "rolled" in "System.out.println ("Five rolls of a die: " + (array[1]) + " " + (array[2]) + " " + (array[3]) + " " + (array[4]) + " " + (array[5]) );
"

Any help would be greatly appreciated.

Thanks,

MC

Fang
09-18-2008, 02:35 AM
Java is not the same as JavaScript
Thread moved ...

chazzy
09-18-2008, 09:58 AM
As you can see I'm having some trouble figuring out how to randomly pick 2 out of the 5 arrays I "rolled" in "System.out.println ("Five rolls of a die: " + (array[1]) + " " + (array[2]) + " " + (array[3]) + " " + (array[4]) + " " + (array[5]) );
"

Any help would be greatly appreciated.

Thanks,

MC


I don't see why. You have the principle down with the first half of this code. This code block should explain what you do have to do though.


int idx1 = 0, idx2 = 0;
while(idx1 != idx2) {
idx1 = generator.nextInt(5);
idx2 = generator.nextInt(5);
}


Then use idx1 and idx2 to get the values from the array.

nvibest
09-18-2008, 06:24 PM
Oh I see now. Thanks a lot.