Question

I want to remove values from a copy of an ArrayList without affecting the original copy. Code currently:
statsOf2Pairs runs first then statsOfFullHouse, but the original list is has its values removed when I remove them from a copy in statsOf2Pairs.

public void statsOf2Pairs(List<List<Integer>> allRolls) {
        long count = 0;
        long debug = 0;
        List<List<Integer>> rolls = new ArrayList<List<Integer>>();
        rolls = allRolls;
        for (List<Integer> roll : rolls) {
            if(roll.size() < 5) {
                debug++;
            }
            if (hasMultiplesOf(roll, 2)) {
                roll.removeAll(Arrays.asList(mRepeatedDice));
                if (hasMultiplesOf(roll, 2)) {
                    count++;
                }
            }
        }
        System.out.println("The amount of 2 pairs in all the rolls possible: "
                + count);
        System.out.println("So the chance of rolling 2 pairs is: "
                + ((double) count / (double) mTotalPossibleRolls) * 100d + " %");
    }

    public void statsOfFullHouse(List<List<Integer>> allRolls) {
        long count = 0;
        long debug = 0;
        for (List<Integer> roll : allRolls) {
            if(roll.size() < 3) {
                debug++;
            }
            if (hasMultiplesOf(roll, 3)) {
                roll.removeAll(Arrays.asList(mRepeatedDice));
                if (hasMultiplesOf(roll, 2)) {
                    count++;
                }
            }
        }
        System.out.println("The amount of Full Houses in all the rolls possible: "
                + count);
        System.out.println("So the chance of rolling a Full House is: "
                + ((double) count / (double) mTotalPossibleRolls) * 100d + " %");
    }

Answer 1

I assume you are wanting to copy the allRolls array instead of assign it to rolls.
Instead of

rolls = allRolls;

Try

List<List<Integer>> rolls = new ArrayList<List<Integer>>(allRolls);

This will create a new list (shallow copy) of the allRolls list. The original example was assigning the allRolls to rolls, not copying it.