I'm having a lot of trouble turning an array into an ArrayList
in Java. This is my array right now:
Card[] hand = new Card[2];
"hand" holds an array of "Cards". How this would look like as an ArrayList
?
ArrayList cloned = new ArrayList(collection c); where c is the collection containing elements to be added to this list. Approach: Create a list to be cloned. Clone the list by passing the original list as the parameter of the copy constructor of ArrayList.
ArrayList allows duplicate values while HashSet doesn't allow duplicates values. Ordering : ArrayList maintains the order of the object in which they are inserted while HashSet is an unordered collection and doesn't maintain any order.
A better way (both time complexity and ease of implementation wise) is to remove duplicates from an ArrayList is to convert it into a Set that does not allow duplicates. Hence LinkedHashSet is the best option available as this do not allows duplicates as well it preserves the insertion order.
This will give you a list.
List<Card> cardsList = Arrays.asList(hand);
If you want an arraylist, you can do
ArrayList<Card> cardsList = new ArrayList<Card>(Arrays.asList(hand));
As an ArrayList
that line would be
import java.util.ArrayList; ... ArrayList<Card> hand = new ArrayList<Card>();
To use the ArrayList
you have do
hand.get(i); //gets the element at position i hand.add(obj); //adds the obj to the end of the list hand.remove(i); //removes the element at position i hand.add(i, obj); //adds the obj at the specified index hand.set(i, obj); //overwrites the object at i with the new obj
Also read this http://docs.oracle.com/javase/6/docs/api/java/util/ArrayList.html
List<Card> list = new ArrayList<Card>(Arrays.asList(hand));
declaring the list (and initializing it with an empty arraylist)
List<Card> cardList = new ArrayList<Card>();
adding an element:
Card card;
cardList.add(card);
iterating over elements:
for(Card card : cardList){
System.out.println(card);
}
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