Minesweeper hashset

Question

I am writing a Minesweeper game, and I am trying to use a hashset. My question is can a hashset contain both integers and strings? The hastset I am using has mainly strings and one that is a integer. Can this be done? When I compile it, it gives me the error that the variable _minecount cannot be found, nothing about it not being a string. This is my code:

    import java.util.Set;
import java.util.HashSet;

/**
 * Represents a single square in Minesweeper.
 * 
 * @author Sophia Ali
 */
public class MineSquare
{
    //Constants:
    // Fields:
    private  String  _shown;      // What a square is showing now
    private  boolean _mined;      // Square is mined or not
    private  boolean _flagged;    // Square is flagged or not
    private  boolean _questioned; // Square is question marked or not
    private  int     _minecount;  // Square's surrounding mine count
    private  boolean _opened;     // Player has opened this square or not
    private static final String[] VALID_SHOWN_TEXT = {"X", 0 < minecount && _minecount < 8, " ", "F", "?"};
    private HashSet<String> validShownTextSet = 
    new HashSet<String>(java.util.Arrays.asList(VALID_SHOWN_TEXT));

    // Constructors & Methods:

    /**
     * Default constructor
     * Sets _mined and _opened to false.
     */
    public MineSquare()
    {
        _mined = false;
        _opened = false;
        setShown(" ");
    }





    /**
     * Returns flagged status of square.
     * @return  _flagged    Flagged status
     */
    public boolean isFlagged() {
        return _flagged;
    }





    /**
     * Sets or unsets flag on a square.
     * @param   flagged    True or false (square is flagged or not)
     */
    public void setFlagged(boolean flagged, boolean opened) {
        _flagged = flagged;
        _opened = opened;

        // If Minesquare opened do nothing:
        if (opened == true)
        setShown(" ");

        // If flagged, square should show "F":
        if ( isFlagged() == true )
            setShown("F");
        else
            setShown(" ");            
    }


    public int getMinecount() {
        return _minecount;
    }





    public void setMinecount(int minecount) {
        _minecount = minecount;

        if ( 0 < minecount && minecount < 8 ) 
        {
       setShown("Error:" + minecount);

    }
}





    public boolean isMined() {
        return _mined;
    }





    public void setMined(boolean mined) {
        _mined = mined;


    }





    public boolean isOpened() {
        return _opened;
    }





    /**
     * Open a square.
     * (Once opened, a square can't be unopened.)
     */
    public void setOpened() {
        _opened = true;

        if ( isMined() == true )
            setShown("X");
        else if ( getMinecount() > 0 )
            setShown(_minecount + "");
        else // blank space for _minecount = 0
            setShown(" ");
    }





    public boolean isQuestioned() {
        return _questioned;
    }





    public void setQuestioned(boolean questioned, boolean opened) {
        _questioned = questioned;
        _opened = opened;
        // If Minesquare opened do nothing:
        if (opened == true)
        setShown(" ");

        // If Questioned, square should show "F":
        if ( isQuestioned() == true )
            setShown("F");
        else
            setShown(" ");  
    }





    public String getShown() {
        return _shown;
    }





    public void setShown(String shown) {
        _shown = shown;
        /*if (shown.equals("X")) {
            this.shown = shown;
        } else if (shown.equals( 0 < minecount && minecount < 8 )) {
            this.shown = shown;
        } else if (shown.equals(" ")) {
            this.shown = shown;
        } else if (shown.equals("F")) {
            this.shown = shown;
        } else if (shown.equals("?")) {
            this.shown = shown;
        } else {
            this.shown = "Error + shown";
        }
        */
       if (validShownTextSet.contains(shown)) {
           this.shown = shown;
        } else {
            this.shown = "Error" + shown;
        }
    }





    }

Answer 1

This line

private static final String[] VALID_SHOWN_TEXT = {"X", 0 < minecount && _minecount < 8, " ", "F", "?"};

has a few problems. There is no minecount variable in scope here. The variable _minecount is not a static variable, so it is inaccessible from the static scope you have made by making VALID_SHOWN_TEXT static.

And as it looks like you've guessed, you cannot store the boolean from the expression 0 < minecount && _minecount < 8 into a String array. Even if you can get a boolean expression working, you'll have to convert it to a String to store it into a String array.

// or a working boolean expression here.
..., String.valueOf(0 < minecount && _minecount < 8), ...

A HashSet<Object> can contain both integers and strings, but here, it looks like you can simply convert what you need into a string array, which should be able to be converted into a HashSet<String> .