java - Having trouble creating Card class -

im having trouble converting r[rank] string. eclipse keeps saying needs resolved array. having trouble cards[13*i + j] = new card(i, j); keeps saying cannot resolved variable. heres code...

public class card {      private string suit;     private string rank;     private static string[] s = { "hearts", "spades", "diamonds", "clubs" };     private static string[] r  = { "ace", "2", "3", "4", "5", "6", "7", "8", "9", "10", "jack", "queen", "king" };      public card(int suit, int deck){         for(int = 0; < 4; i++) {             for(int j = 0; j < 13; j++){                cards[13*i + j] = new card(i, j);              }         }     }      public card(string r, string s, string suit){         for(int rank = 0; rank < r.length(); rank+=1){             if( rank.equals(r[rank]) ){                 this.rank = r+1;             }         }         this.suit = suit;     }      public string getsuit(){         return suit;     }      public void setsuit(string a, string suit) {         this.suit = suit;     }      public string getrank(){         return rank;     }     public void setrank( string s, string rank){         this.rank= rank;     }      public string tostring(){         return string.valueof(this.getrank()) + string.valueof(this.getsuit().charat(0));     }  } 

public class deck {

private card[] deck; private int indeck; private final int size_of_deck = 52;  private int currentcard;  public deck(){     deck = new card[deck]; }  private void init(){  }  public void shuffle(int num){     int i,j,k;     (k = 0; k < num; k++)     {         = (int) (size_of_deck * math.random()*100);         j = (int) (size_of_deck * math.random()*100);          card tmp = deck[i];         deck[i] = deck[j];         deck[j] = tmp;     }     currentcard = 0; }  public card getcard(){     if (currentcard<size_of_deck)     {         return deck[currentcard++];     }     else     {         system.out.print("out of cards error");         return null;     }     }  public int totalcards(){     return size_of_deck ;} 

}

you never initialize card array... try along lines of before create each individual object loops.

card[] cards = new card[52];