Thread: Java beginner - help needed!

I am taking a Java class and I am pretty lost.

The assignment is:
create a JFrame that will hold a series of 5 panels. The first 4 panels will randomly show different shapes (oval, circle, and square). The fifth panel will display the word “JACKPOT” if all 4 of the other panels contain a square and will display the word “RATS” if they have any other combination

I keep track of how many of each shape appear, yet I get some weird incorrect results when I use System.out.println() to try to debug it. I also do not know if I need to display JACKPOT or RATS on the final panel as I can't get the results back to my main jackpot.java file.

Help?

jackpot.java:

import javax.swing.*;
import java.awt.*;
import java.util.Random;
 
public class jackpot{
 
	public static void main(String [] args){
 
		JFrame theGUI = new JFrame();
		theGUI.setTitle("Test your luck!");
		theGUI.setSize(750,180);
 
		theGUI.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 
		Container pane = theGUI.getContentPane();
		pane.setLayout(new GridLayout(1,5));
 
		for(int i =1; i <= 4; i++){
 
			Random gen = new Random();
 
			int ran = gen.nextInt(3);
 
			ColorPanel panel = new ColorPanel(Color.black);
			pane.add(panel);
		}
 
		JPanel panel = new JPanel();
		panel.setBackground(Color.black);
		pane.add(panel);
 
		theGUI.setVisible(true);
	}
}

ColorPanel.java:

import javax.swing.*;
import java.awt.*;
import java.util.Random;
 
public class ColorPanel extends JPanel{
 
	int rect = 0, oval = 0, circle = 0;	
 
	public ColorPanel(Color backColor){
		setBackground(backColor);
	}
 
	public void paintComponent(Graphics g){
 
		super.paintComponent(g);
 
		int width = getWidth() - 1;
		int height = getHeight() - 1;
 
		g.setColor(Color.white);
 
		Random gen = new Random();
 
		int ran = gen.nextInt(3);		
 
		if(ran==0){
			g.fillRect(0,0,width-5,height);
			rect++;
		}else if(ran==1){
			g.fillOval(0,5,width-5,height/2);
			oval++;
		}else{
			g.fillOval(0,0,width-5,height);
			circle++;
		}
 
		//g.setColor(Color.white);
		//g.drawString("RATS",0,0);
 
	}	
}

Welcome to the forum! Thanks for taking the time to learn how to post code correctly. If you haven't already, please read this topic to learn other useful info for new members.

Please respect Java's naming conventions and title your classes with names that begin with capital letters.

All data is (or could be) created in your main() method, so you don't really need to get something "back" from somewhere else. Choose the shapes drawn in the JPanels based on random numbers generated in the main() method which are passed to the ColorPanel() constructor. Keep track of how many of each random number is generated. If the random number generator results in 3 of the same numbers, you have a winner, otherwise a loser.

Other points:

Move the bulk of your code from the main() method to a constructor and supporting methods. I recommend you add another class, "OneArmedBandit" (you pick the name). The Test class should kickoff the OneArmedBandit class that then uses the ColorPanel class to display the results. Separate the logic (OneArmedBandit) from the GUI (ColorPanel).

Do not generate a new Random object each time through the loop. One Random object will do and will help the Random illusion. Seed the Random() constructor. (Refer to the Random API).

Add an attribute to your ColorPanel class that defines the shape and/or text contained in the panel.

Remove most logic (Random, ifs, etc.) from inside the paintComponent() method, reducing it to the logic needed to paint the panel.