I am decently new at programming (just took my 1302 final) so don't be extremely pedantic but I am looking for constructive criticism. I am glad with my product and it is not nearly finished so there will be improvements, keep in mind this only took around a few hours of work. I am also happy with it due to how short the code is. Everywhere I look calculator code examples are about to same length or slightly longer. So, tell me what you think! I would love to hear how to shorten the code. [quote] import java.awt.Color; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JTextField; import javax.swing.SwingUtilities; public class Main extends JFrame{ public JButton button1 = new JButton("1"); public JButton button2 = new JButton("2"); public JButton button3 = new JButton("3"); public JButton button4 = new JButton("4"); public JButton button5 = new JButton("5"); public JButton button6 = new JButton("6"); public JButton button7 = new JButton("7"); public JButton button8 = new JButton("8"); public JButton button9 = new JButton("9"); public JButton button0 = new JButton("0"); public JButton mult = new JButton("*"); public JButton add = new JButton("+"); public JButton sub = new JButton("-"); public JButton div = new JButton("/"); public JButton equals = new JButton("="); public JButton per = new JButton("."); public JButton clear = new JButton("Clear"); public JTextField display = new JTextField(); public JTextField displaywarning = new JTextField(); JLabel frame = new JLabel(); JFrame component = new JFrame(); //public int selected; public int operation; public double first; public ActionEvent e1; Main(){ display.setSize(240, 70); display.setLocation(50, 50); display.setVisible(true); display.setBackground(Color.WHITE); display.setEditable(false); displaywarning.setSize(240,30); displaywarning.setLocation(50,10); displaywarning.setVisible(true); displaywarning.setBackground(Color.GRAY); displaywarning.setEditable(false); button1.setVisible(true); button1.setSize(60, 25); button1.setLocation(50,200); button1.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e1) { //selected=1; display.setText(display.getText()+1); } }); button2.setVisible(true); button2.setSize(60, 25); button2.setLocation(110,200); button2.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e1) { //selected=2; display.setText(display.getText() + 2); } }); button3.setVisible(true); button3.setSize(60, 25); button3.setLocation(170,200); button3.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e1) { display.setText(display.getText() + 3); } }); div.setVisible(true); div.setSize(60, 25); div.setLocation(230,175); div.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e1) { first = Double.parseDouble(display.getText()); operation = 1; display.setText(""); displaywarning.setText("" + first + " / "); } }); clear.setVisible(true); clear.setSize(240, 25); clear.setLocation(50,250); clear.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e1) { display.setText(""); } }); per.setVisible(true); per.setSize(60, 25); per.setLocation(230,200); per.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e1) { display.setText(display.getText()+ "."); } }); mult.setVisible(true); mult.setSize(60, 25); mult.setLocation(230,150); mult.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e1) { first = Double.parseDouble(display.getText()); operation = 4; display.setText(""); displaywarning.setText("" + first + " * "); } }); equals.setVisible(true); equals.setSize(60, 25); equals.setLocation(230,225); equals.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e1) { displaywarning.setText(displaywarning.getText() + display.getText()); if(operation == 1) { if(Integer.parseInt(display.getText())==0) { displaywarning.setText("Can't divide by zero."); first=0; display.setText(""); } else display.setText("" + (first / Double.parseDouble(display.getText()))); } if(operation == 2) display.setText("" + (first - Double.parseDouble(display.getText()))); if(operation == 3) display.setText("" + (first + Double.parseDouble(display.getText()))); if(operation == 4) display.setText("" + (first * Double.parseDouble(display.getText()))); } }); sub.setVisible(true); sub.setSize(60, 25); sub.setLocation(170,225); sub.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e1) { first = Double.parseDouble(display.getText()); operation = 2; display.setText(""); displaywarning.setText("" + first + " - "); } }); add.setVisible(true); add.setSize(60, 25); add.setLocation(110,225); add.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e1) { first = Double.parseDouble(display.getText()); operation = 3; display.setText(""); displaywarning.setText("" + first + " + "); } }); button4.setVisible(true); button4.setSize(60, 25); button4.setLocation(50,175); button4.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e1) { //selected=4; display.setText(display.getText() + 4); } }); button5.setVisible(true); button5.setSize(60, 25); button5.setLocation(110,175); button5.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e1) { //selected=5; display.setText(display.getText() + 5); } }); button6.setVisible(true); button6.setSize(60, 25); button6.setLocation(170,175); button6.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e1) { //selected=6; display.setText(display.getText() + 6); } }); button7.setVisible(true); button7.setSize(60, 25); button7.setLocation(50,150); button7.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e1) { //selected=7; display.setText(display.getText() + 7); } }); button8.setVisible(true); button8.setSize(60, 25); button8.setLocation(110,150); button8.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e1) { //selected=8; display.setText(display.getText() + 8); } }); button9.setVisible(true); button9.setSize(60, 25); button9.setLocation(170,150); button9.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e1) { //selected=9; display.setText(display.getText() + 9); } }); button0.setVisible(true); button0.setSize(60, 25); button0.setLocation(50,225); button0.addActionListener(new ActionListener() { @Override public void actionPerformed(ActionEvent e1) { //selected=0; display.setText(display.getText() + 0); } }); //Main frame frame.add(display); frame.add(button1); frame.add(button2); frame.add(button3); frame.add(button4); frame.add(button5); frame.add(button6); frame.add(button7); frame.add(button8); frame.add(button9); frame.add(button0); frame.add(div); frame.add(sub); frame.add(add); frame.add(equals); frame.add(mult); frame.add(per); frame.add(clear); frame.add(displaywarning); component.add(frame); component.setTitle("Colby's Calculator"); component.setVisible(true); component.setSize(340,320); component.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); component.setResizable(false); } public static void main(String[] args){ Main calculator = new Main(); } } [/quote]