ContainsAll array list issue Java -


so i'm trying use containsall built in list method compare 2 arrays

i used contains method single values , works perfectly, contains doesn't.

i'm making card game i'm checking whether set of cards in set of cards

so:

  if(this.hand.containsall(hand.getcards())){

however statement keeps returning false..

here's constructor

  private arraylist<card> hand;      public hand(arraylist<card> hand) {             this();             this.hand.addall(hand);         }

here's cards method

 public arraylist<card> getcards() {         return this.hand;     }

unsure why code isn't returning true containsall it's fine when done individually, there common concept haven't considered?

any pointers bonus

thank you

edit:

this returns true when used :

works

public boolean hascard(card card){    if (this.hand.contains(card)){        return true;    } }

doesn't

public boolean hascards(hand hand){     if(this.hand.containsall(hand.getcards()){     return true } }

main..

    card 1 = new card(card.rank.ace, card.suit.clubs);             card 2 = new card(card.rank.ace, card.suit.diamonds);             card 3 = new card(card.rank.two, card.suit.spades);             card 4 = new card(card.rank.six, card.suit.randsuit());             card 5 = new card(card.rank.seven, card.suit.randsuit());             arraylist<card> cards = new arraylist<>();             cards.add(one);             cards.add(two);             cards.add(three);             cards.add(four);             cards.add(five);             hand h = new hand(cards);      card ones = new card(card.rank.ace, card.suit.clubs);         card twos = new card(card.rank.ace, card.suit.diamonds);         card threes = new card(card.rank.two, card.suit.spades);         arraylist<card> cards2 = new arraylist<>();  // works h.hascard(five);  // doesn't h.hascards(h2);           cards2.add(ones);         cards2.add(twos);         cards2.add(threes);         hand h2 = new hand(cards2);

try h.hascard(new card(card.rank.ace, card.suit.clubs)). fill return false. h.hascard(one) returns true.

to understand why, try this: one.equals(new card(card.rank.ace, card.suit.clubs). these 2 instances of same card, java has no way of knowing it. 2 different objects.

you added one h hand, so, when looking object, find it. searching object new card(card.rank.ace, card.suit.clubs) fails, because java not know represents same card.

to fix this, have override equals message on card, , make return true objects correspond same card.

your containsall call isn't working same reason: hand contains cards, represented different objects. implementing equals method fix well.


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