Thread: HashMap Shuffle Card

Hi can u help me what's wrong in my code.
I used a HasMap Method for shuffling of Cards.
but it has still a wrong code. and it is in the HashMap Method.

Here's my code:

import java.util.*;
 
public class WarGame {
	public static void main(String[] args) {
 
		String deckInitial = "A/D, K/D, Q/D, J/D, 10/D, 9/D, 8/D, 7/D, 6/D, 5/D, 4/D, 3/D, 2/D, A/H, K/H, Q/H, J/H, 10/H, 9/H, 8/H, 7/H, 6/H, 5/H, 4/H, 3/H, 2/H, A/S, K/S, Q/S, J/S, 10/S, 9/S, 8/S, 7/S, 6/S, 5/S, 4/S, 3/S, 2/S, A/C, K/C, Q/C, J/C, 10/C, 9/C, 8/C, 7/C, 6/C, 5/C, 4/C, 3/C, 2/C";
		String deckRank = "A/D, A/H, A/S, A/C, K/D, K/H, K/S, K/C, Q/D, Q/H, Q/S, Q/C, J/D, J/H, J/S, J/C, 10/D, 10/H, 10/S, 10/C, 9/D, 9/H, 9/S, 9/C, 8/D, 8/H, 8/S, 8/C, 7/D, 7/H, 7/S, 7/C, 6/D, 6/H, 6/S, 6/C, 5/D, 5/H, 5/S, 5/C, 4/D, 4/H, 4/S, 4/C, 3/D, 3/H, 3/S, 3/C, 2/D, 2/H, 2/S, 2/C";
 
		System.out.println ("Deck of Cards - Initial: " + deckInitial);
 
		HashMap <String, Integer> deck1 = new HashMap <String, Integer> ();
		HashMap <String, Integer> rank1 = new HashMap <String, Integer> ();
 
 
		StringTokenizer str1 = new StringTokenizer (deckInitial, ",");
		while (str1.hasMoreTokens()){
		 	for (int i=0; i<52; i++){
		 		deck1.add(str1.nextToken(), (i));
		 	}
		}
 
		StringTokenizer str2 = new StringTokenizer (deckRank, ",");
		while (str2.hasMoreTokens()){
		 	for (int i=0; i<52; i++){
		 		rank1.add(str2.nextToken(), (i));
		 	}
		}
 
 
		HashMap<String, Integer> rd = new HashMap<String, Integer>();
		for (int i=0; i<52; i++){
			rd.add(rank1.pop(), (i));
		}
 
		//Shuffle
		Integer shuffleInput = null;
 
		HashMap<String, Integer> deck2 = new HashMap<String, Integer>();
		HashMap<String, Integer> deck3 = new HashMap<String, Integer>();
		HashMap<String, Integer> deckFinal = new HashMap<String, Integer>();
 
		Scanner input = new Scanner (System.in);
		System.out.print("\nEnter number of Shuffle: ");
 
		if (input.hasNextInt()){
			shuffleInput = input.nextInt();
						}
 
		while(shuffleInput != 0){
			do {
				deck2.add(deck1.pop());
					}while (deck2.size() != 26);
 
			do {
				deck3.add(deck1.pop());
					}while (deck3.size() != 26);
 
			do{
				deckFinal.add(deck2.pop());
				deckFinal.add(deck3.pop());
					}while(!deck3.isEmpty() && !deck2.isEmpty());
						shuffleInput--;
 
					if(shuffleInput != 0){
						deck1 = deckFinal;
					}
				}
 
		System.out.println("\nDeck of Cards - Shuffled: " + deckFinal);
	}
 
}

Originally Posted by d'fitz

but it has still a wrong code

Do you honestly think that people will be able to help without a more detailed explanation than that?

Why are you using HashMaps at all? Just create a Card class that has a rank and suit. Then have a List of Card objects. Much cleaner.

we are required to use HashMap so we can have a key and value for each card.
so that when the time comes that we will deal/compare the cards, it will have a key and value.

I'm just a beginner here in java though.
So I'm having a hard time. Btw, thanks for d answer.

OK so you are required to use HashMap but why do have six of them? You only need one. Clean your code up and you might be able to see things more clearly.

Another thing, shuffling a Map makes no sense. The items are placed into "buckets" based on some hashing funtion. They are not stored in any particular order thus they cannot be shuffled.

Surely it would be better design to have a Card class containing both the value and name/description/key? Then you can put them into a deck List (e.g. ArrayList) and sort or shuffle them however you want using the Collections API.