Question

Write an application that extends JFrame and that displays diagonal lines in a square, like those in the figure below. Save the file as JDiagonalLines.java.

$xid-1453787_1$

Output of the JDiagonalLines program

Answer 1

Program:

import java.awt.Color;
import java.awt.Graphics;
import javax.swing.JFrame;

public class NewJFrame extends javax.swing.JFrame {
private int side = 200;
public NewJFrame()
{
// initComponents();
// Set JFrame title
super("Square with Diagonals");
//Set default close operation for JFrame
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//Set JFrame size
setSize(400,400);
//Make JFrame visible   
setVisible(true);
}

public void paint(Graphics g)
{
super.paint(g);   
//draw square outline
int x=50,y=50; // starting position of square
g.setColor(Color.BLUE);
g.drawRect(x,y,side,side);
g.setColor(Color.RED);
g.drawLine(x, y, x+side, y+side);// diagonal1
g.drawLine(x+side, y, x, y+side); // Diagonal2   
}

public static void main(String args[]) {

NewJFrame nf=new NewJFrame();
}   

}

//OUTPUT