Calculator Program:

import java.awt.*; import javax.swing.*;

public class Calculator extends JFrame { JTextField display;// Display text field. JPanel buttonPanel;// Panel for buttons. JButton buttons[];// Array to create button objects.

Calculator() { super("Calculator");// Gives the frame the title of Calculator.

display = new JTextField();// Creates and stores the object of the text // field in the display. buttons = new JButton[16];// Array made up of 16 variables to signify // buttons. buttons[0] = new JButton("7");// Seven button. buttons[1] = new JButton("8");// Eight button. buttons[2] = new JButton("9");// Nine button. buttons[3] = new JButton("/");// Divide button. buttons[4] = new JButton("4");// Four button. buttons[5] = new JButton("5");// Five button. buttons[6] = new JButton("6");// Six button. buttons[7] = new JButton("*");// Multiply button. buttons[8] = new JButton("1");// One button. buttons[9] = new JButton("2");// Two button. buttons[10] = new JButton("3");// Three button. buttons[11] = new JButton("-");// Subtract button. buttons[12] = new JButton("0");// Zero button. buttons[13] = new JButton(".");// Dot button. buttons[14] = new JButton("=");// Equals button. buttons[15] = new JButton("+");// Add button.

buttonPanel = new JPanel();// Creates panel for buttons. buttonPanel.setLayout(new GridLayout(4, 4, 5, 5));// Sets the layout of // the buttons in a // grid format.

for (int i = 0, j = 0; i < 16; i++)// For statement to place buttons, // set font, set background and // foreground of buttons. { buttons[i].setFont(new Font("SanSerif", Font.BOLD, 16));// Sets the // font to // SanSerif, // BOLD and // to size // 16. if (i % 4 == 0) j++; if (j++ % 2 == 0) { buttons[i].setBackground(Color.GREEN);// Sets the background of // the 8, /, 4, 6, 2, -, // 0, = buttons to // green. buttons[i].setForeground(Color.BLACK);// Sets the // foreground(numbers) // of the 8, /, 4, 6, 2, // -, 0, = buttons to // black. } else { buttons[i].setBackground(Color.BLACK);// Sets the background of // the 7, 9, 5,*, 1, 3,. // , + buttons to black. buttons[i].setForeground(Color.GREEN);// Sets the foreground of // the 7, 9, 5,*, 1, 3,. // , + buttons to green. }

buttonPanel.add(buttons[i]); } add(display, BorderLayout.NORTH);// Sets the display(text field) at the // top of the frame. add(buttonPanel, BorderLayout.CENTER);// Sets the buttons in the center // of the frame to fill the // space below with buttons. setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);// Allows the program to // close when the X // button is pressed. setSize(250, 250);// Sets the size of the frame to 250 x 250 pixels. setVisible(true);// Allows the user to see the calculator frame. }

public static void main(String[] args) { Calculator calculator = new Calculator(); }
}

Alignment GUI Program:

import javax.swing.*; import java.awt.*;

public class Align { private JFrame frame; private JButton okJButton; private JButton cancelJButton; private JButton helpJButton; private JTextField xJTextField; private JTextField yJTextField; private JCheckBox snapJCheckBox; private JCheckBox showJCheckBox; private JLabel xJLabel; private JLabel yJLabel; private JPanel checkJPanel; private JPanel buttonJPanel; private JPanel fieldJPanel1; private JPanel fieldJPanel2; private JPanel fieldJPanel;

// Constructor creates the GUI public Align() { // Builds the checkJPanel specific to check boxes. snapJCheckBox = new JCheckBox("Snap to Grid"); // Creates the // "Snap to Grid" check // box. showJCheckBox = new JCheckBox("Show Grid"); // Creates the "Show Grid" // check box. checkJPanel = new JPanel();// Creates the panel for the check boxes. checkJPanel.setLayout(new GridLayout(2, 1)); // uses layoutManager(grid // layout) checkJPanel.add(snapJCheckBox); // Adds "Snap to Grid" check box. checkJPanel.add(showJCheckBox); // Adds the "Show Grid" check box.

// Builds field panel1 specific to X label and text field. xJLabel = new JLabel("X: "); xJTextField = new JTextField("", 3); // Sets the width of the text // field. fieldJPanel1 = new JPanel();// Creates panel for the X label and X text // field. fieldJPanel1.setLayout(new FlowLayout()); // Uses flow layout layout // manager fieldJPanel1.add(xJLabel); // Adds the X label. fieldJPanel1.add(xJTextField); // Adds the X text field.

// Builds field panel2 specific to Y label and text field. yJLabel = new JLabel("Y: "); yJTextField = new JTextField("", 3); // Sets the width of the text // field. fieldJPanel2 = new JPanel();// Creates panel for the Y label and Y text // field. fieldJPanel2.setLayout(new FlowLayout()); // Uses flow layout layout // manager fieldJPanel2.add(yJLabel); // Adds the Y label. fieldJPanel2.add(yJTextField); // Adds the Y text field.

// Build field panel. fieldJPanel = new JPanel(); fieldJPanel.setLayout(new BorderLayout()); // Uses border layout to set // locations of the field // panel 1 and 2. fieldJPanel.add(fieldJPanel1, BorderLayout.NORTH);// Sets field panel 1 // to the north(or // top). fieldJPanel.add(fieldJPanel2, BorderLayout.SOUTH);// Sets field panel 2 // to the // south(bottom).

// Builds the button panel. okJButton = new JButton("Ok"); // Creates the OK button. cancelJButton = new JButton("Cancel"); // Creates the Cancel Button. helpJButton = new JButton("Help");// Creates the Help button. buttonJPanel = new JPanel();// Creates the panel for the buttons used. buttonJPanel.setLayout(new GridLayout(3, 1, 10, 5));// Uses a grid // layout to place // the buttons in // position. buttonJPanel.add(okJButton); // Adds the OK button in the grid layout. buttonJPanel.add(cancelJButton);// Adds the Cancel button in the grid // layout. buttonJPanel.add(helpJButton);// Adds the Help button in the grid // layout.

// Uses flow layout for center-aligned and add components frame = new JFrame("Align");// Gives the title of the frame and sets it // to "Align." frame.setLayout(new FlowLayout(FlowLayout.CENTER, 10, 5));// Sets the // layout to // center // and sets // spacing // to 10 X // 5. frame.add(checkJPanel);// Adds the check box panel to the frame. frame.add(fieldJPanel);// Adds the text field panel to the frame. frame.add(buttonJPanel);// Adds the button panel to the frame.

frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);// Closes the frame // by pressing // the X button. frame.pack(); frame.setVisible(true);// Allows the frame to be visible to the user. }

public static void main(String[] args) { Align align = new Align(); }
}