Thread: My code cannot display the Car [HELPED]

Hello friends, i am new to this forum, sorry if i break some rules in this forum ( please notice me)

this is my code, i don't know what is wrong with it...it should display a car that is moving but it doesn't

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
 
public class RacingCar extends JFrame{
 
	public RacingCar(){
		add(new MovingCar());
	}
 
	public static void main(String[] args){
		JFrame frame = new RacingCar();
		frame.setTitle("Racing car");
		frame.setLocationRelativeTo(null);
		frame.setSize(300,300);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.setVisible(true);
	}
 
	static class MovingCar extends JPanel{
		private int x = 0;
		private int y = 100;
		public MovingCar(){	
			Timer timer = new Timer(1000, new TimerListener() );
			timer.start();
		}
 
		public MovingCar(int x, int y){
			this.x = x;
			this.y = y;
 
			Timer timer = new Timer(1000, new TimerListener() );
			timer.start();
		}
 
		public void paintComponent(Graphics g){	
			super.paintComponent(g);
 
 
			if( x > getWidth() )
				x = - 20;
			x += 5;
 
 
			// call the body
			add(new constructBody(x,y));
 
		}
 
		// class for timing
		class TimerListener implements ActionListener{
			public void actionPerformed(ActionEvent e){
				repaint();
			}
		}
 
		// class for constructing the body
		static class constructBody extends JPanel{
			private int x = 0;
			private int y = 0;
 
			public constructBody(int x, int y){
				this.x = x;
				this.y = y;
 
			}
 
			public void paintComponent(Graphics g){
				super.paintComponent(g);
				int xTra [] = {x + 20, x + 30, x + 40,  x + 10};
				int yTra [] = {y - 30, y - 30, y - 20, y - 20};
				g.setColor(Color.RED);
				g.fillPolygon(xTra, yTra, xTra.length);
				g.setColor(Color.gray);
				g.fillRect(x, y - 20, 50 , 10);
				g.setColor(Color.black);
				g.fillOval(x + 10, y - 10, 10, 10);
				g.setColor(Color.black);
				g.fillOval(x + 30, y - 10, 10 , 10);
 
			}
		}
 
 
	}
}

Are you getting any error messages? Is there a part of the program you think
is causing the problem?

Wishes Ada xx

Try debugging the code by adding some println statements to all the methods and constructors to see which one are being executed.

To see where a component has been placed and how big it is, add a call to getBounds() to the debugging println() statements.