How to assign or initiate an integer into JButton?

Question

package javaapplication3;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;

class BattleShip2 extends JFrame implements ActionListener {
    JButton[][] array2dtop = new JButton[10][10];
    BattleShip2(String title) { //Board Display
        super(title);//show Title
        setLayout(new FlowLayout()); // button posistion
         for(int x = 0; x < array2dtop.length; x++) {
            for(int y = 0; y < array2dtop.length; y++) {
                array2dtop[x][y] = new JButton(String.valueOf((x * 10) + y)); //display   
                array2dtop[x][y].setBounds(20,40,140,20);
                array2dtop[x][y].setActionCommand("x"); //itself value
                array2dtop[x][y].addActionListener(this);
                add(array2dtop[x][y]);
            }
        }

    }

    public void actionPerformed(ActionEvent evt) { //operation
        String cmd = evt.getActionCommand();

        if(cmd == "x") {
            System.out.println("x");
        }
    }

}

public class pratice3 {
    public static void main(String[] args) {
        BattleShip2 board = new BattleShip2("BattleShip");
        board.setSize(500, 400);
        board.setLocation(250, 250);
        board.setDefaultCloseOperation(board.EXIT_ON_CLOSE); //Press x to EXIT
        board.setVisible(true);
    }
}

Hi, i am creating a battleship game, and my idea is when the user or AI hit the button, it could show ship size For example, there have 3 ships: ship1(size = 3), ship2(size = 2), ship3(size = 1), and when the user/AI hit the ship1, and they see 3, they will know they hit ship1

but I am having troubles on the setActioncommand

on the code,

array2dtop[x][y].setActionCommand("x")

I want to assign or declare a integer(the size of the ship) into array2dtop[x][y] but I have no idea but assign a string and how can I use it in the actionPerformed

Answer 1

I want to assign or declare a integer(the size of the ship) into array2dtop[x][y]

You can just parse the string to an integer using Integer.parseInt :

class BattleShip2 extends JFrame implements ActionListener {

    JButton[][] array2dtop = new JButton[10][10];

    BattleShip2(String title) {

        super(title);
        setLayout(new GridLayout(10, 10, 5, 5));
        for (int x = 0; x < array2dtop.length; x++) {
            for (int y = 0; y < array2dtop.length; y++) {
                array2dtop[x][y] = new JButton(String.valueOf((x * 10) + y));
                array2dtop[x][y].setActionCommand(String.valueOf(3));
                array2dtop[x][y].addActionListener(this);
                // Force buttons to be square.
                Dimension dim = array2dtop[x][y].getPreferredSize();
                int buttonSize = Math.max(dim.height, dim.width);
                array2dtop[x][y].setPreferredSize(new Dimension(buttonSize, buttonSize));

                add(array2dtop[x][y]);
            }
        }
    }

    public void actionPerformed(ActionEvent evt) {

        int cmd = Integer.parseInt(evt.getActionCommand());
        if (cmd == 3) {
            System.out.println(3);
        }
    }
}

public class pratice3 {

    public static void main(String[] args) {

        BattleShip2 board = new BattleShip2("BattleShip");
        board.pack();
        board.setLocationRelativeTo(null);
        board.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        board.setVisible(true);
    }
}

Notes:

• I changed the layout to GridLayout with the same vertical and horizontal gaps as FlowLayout 's defaults. It will assure that all button have the same size.
• Don't use setBounds , let the layout manager take care of that.
• I added 3 lines that make the buttons square, you can remove that.
• Instead of using setSize for a JFrame , use pack .
• Setting the location using board.setLocationRelativeTo(null) (After the call to pack ) is usually a better idea since you don't know the size of the screen.
• board.EXIT_ON_CLOSE should be accessed in a static way: JFrame.EXIT_ON_CLOSE (for example).
• When calling Integer.parseInt , you might want to catch NumberFormatException .

With that being said, there are other ways to achieve this, such as using setClientProperty on the buttons, or just passing the number to the ActionListener 's constructor.