public class Dice
{
    // The data member dice is a reference variable that 
    // can point to an array of Die objects.
    private Die[] dice;

    public Dice (int numDice)
    {
        dice = new Die[numDice];
		  for (int i=0; i<dice.length; i++) {
            // The constructor for Die does not take parameters,
            // so no parameters should be given.
            dice[i] = new Die();
        }
    }

    /*******************************************
     * roll
     *
     * - Takes no parameters
     * - Returns nothing
     * - Rolls each Die object in the arrry
     *******************************************/
    public void roll()
    {
        // For each element in the dice array, call the
        // roll method to randomly choose a face value
        for (int i=0; i<dice.length; i++) {
            dice[i].roll();
        }
    }

    /*******************************************
     * getDie
     *
     * - Takes an integer parameter, position
     * - Returns the Die object at that position,
     *   or null, if the position is invalid
     *******************************************/
    public Die getDie (int position)
    {
        // Make sure that position is a valid index
        // (between 0 and dice.length)        
        if (position >= dice.length || position < 0) {
            // position is invalid, return null
            return null;
        }
        // position is valid, return the appropriate Die object
        return dice[position];
    }

    /*******************************************
     * getNumDice
     *
     * - Takes no parameters
     * - Returns the length of the dice array
     *******************************************/
    public int getNumDice()
    {
        // The data member dice is private, so classes outside
        // of Dice cannot directly access dice, which also means
        // that they cannot directly access dice.length.
        return dice.length;
    }

    /*******************************************
     * toString
     *
     * - Takes no parameters
     * - Returns a String containing the face values
     *   of all of the Die objects in the array
     *******************************************/
    public String toString()
    {
        // Create a blank String variable
        String diceString = "";

        // For each element in the dice array, add its
        // face value (obtained through dice[i].getFace())
        // to the String.  Separate each element's face
        // by the tab character.
        for (int i=0; i<dice.length; i++) {
            diceString += dice[i].getFace() + "\t";
        }
        // Return the completed String
        return (diceString);
    }

} // end of Dice class