I am trying to convert an array method to an ArrayList method

Question

My method is trying to find a certain card with a suit and a value previously described in enums. My original code is:

public int find(Suit s, Value v) {

    for(int i=0; i<numCards; i++) {
        if(cards[i].getSuit() == s && cards[i].getValue() == v) {
            return i;
        }
    }

    return -1;
}

cards was an array and I've already converted it to an array, but how do I modify the code to apply to an ArrayList? Is there a method I should be using or would HashTables help me?

Answer 1

Maybe this (assuming it's cards that is the arraylist):

 public int find(Suit s, Value v) {
    for(int i=0; i<cards.size(); i++) {
       if(cards.get(i).getSuit()==s && cards.get(i).getValue()==v) {
             return i;
            }
        }
          return -1;
   }

This should traverse through every element in the ArrayList for cards

Answer 2

You should really never use arrays. They are inherently less flexible and reliable.

You should have a Card class like this:

public class Card implements Comparable<Card> {
  public int compareTo(Card other) { return this.value - other.value;}
}

Then have

List<Card> cards;

Notice I am specifying ArrayList or LinkedList .. just List.

Then you can just use

int index = Collections.binarySearch(cards,new Card(...));

Implementing a for loop is just not the way to go.