java - iterate through all combinations of cards -

i'm creating card game , iterate through possible combinations of card.

for example (ace of hearts, 2 of hearts), (ace of hearts, 2 of spades), (ace of hearts, 2 of clubs).... etc

i'm doing in java

currently have this:

to start have

list<card> deckofcards = new arraylist<card>(); 

which deck containing cards. create

queue<card> deckofcardswithoutduplicates = new linkedlist<card>();         deckofcardswithoutduplicates = deckofcards; 

now want iterate through of cards without duplicates.

        (card c : deckofcards) {              deckofcardswithoutduplicates.remove(c);             (card c1 : deckofcardswithoutduplicates) {  //something here irrelevant              }             deckofcardswithoutduplicates.add(c);         } 

however java.util.concurrentmodificationexception . can give me hints on how better?

it's because you're trying remove list you're looping through.

to remove list you're looping through, need use iterator