Java array, NullPointerException?

I declare two cards:

Card card1 = new Card('3',Card.Suit.clubs);
Card card2 = new Card('T',Card.Suit.diamonds);

This works:

Hand hand1 = new Hand();

hand1.takeCard(card1);

But why doesn't it work? It gives me a NullPointerException on the second line:

Hand[] hand = new Hand[2];

hand[0].takeCard(card2);

Solution

You are announcing a set of two hands This is just setting the array Then, you need to instantiate the hand object in the array

say

hand[0] = new Hand(); 
hand[1] = new Hand();