array required, but java.lang.String found card game - arrays

Question

I'm making a deck and card class for a game, and have encountered an error in creating and using a string array.
my code looks like this: The error is 4 lines from the bottom where it says String undealt = ... undealt[0] and it says "array required, but java.lang.String found" and now I am confused
import java.util.*;
public class Deck
{
private static int currentCard = 0;
public ArrayList<Card> deck;
private String rank;
private String suit;
private String[] undealt = new String[52];
Deck(String[] ranks, String[] suits, int[] values)
{
for(int i = 1; i <= suits.length; i++)
{
for(int x = 0; x < ranks.length; x++)
{
Card card = new Card(ranks[x], suits[i], values[x]);
deck.add(card);
}
}
shuffle();
}
public String toString()
{
String undealt = "Undealt cards:\n" + undealt[0] + undealt[1] ...;
for(int i = currentCard; i < deck.size(); i++)
{
int g = i - currentCard;
undealt[g] = deck.get(i).toString();
}
}

Answer 1

The problem which you are having derives from these lines in your code:
private String[] undealt = new String[52];
:
:
public String toString() {
String undealt = "Undealt cards:\n" + undealt[0] + undealt[1] ...;
:
:
}
As you can see, you have defined the variable undealt in two different scopes. The first declaration is at the instance level, where you have declared undealt to be an instance field of type String[]. The scope of an instance variable is the entire class in which it is defined, i.e. an instance variable can be accessed by all methods in that class.
The second declaration is at the local block level, where you have declared undealt to be a local variable of type String. The scope of a local variable is limited to the block in which it is declared (blocks are delimited by curly braces).
As you can see, undealt is in scope twice in the method toString(), once as an instance field, the second time as a local variable. The compiler has rules which it uses to resolve variable names when they conflict in this way, and will use the local variable definition. This is called "hiding" the instance field, i.e. the local variable hides the instance field.
When the compiler tries to compile...
String undealt = "Undealt cards:\n" + undealt[0] + undealt[1] ...;
it determines that String[] undealt is hidden, and it will resolve undealt as type String.
Therefore, when you attempt to use the array element access operator (the brackets after the variable name), the compiler gives you an error. It has determined that undealt is a local String and therefore it does not have any array elements to access.
A good practice is to avoid ever using two variables with the same name in order to avoid potential sources of confusion such as this. The compiler has a set of rules to use to resolve variable accesses in the case of a conflict, but these needn't be obvious to programmers and can cause confusion.