Calculator.java

import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JTextField;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.Font;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

public class Calculator extends JFrame {
    private static final long serialVersionUID = 1L;
    public static float a = 0;
    public static float b = 0;
    protected static int op = 0;
    private JPanel contentPane;
    private JTextField textField;
    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {
            public void run() {
                try {
                    Calculator frame = new Calculator();
                    frame.setVisible(true);
                } catch (Exception e) {
                    e.printStackTrace();
                }
            }
        });
    }
    public Calculator() {
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setBounds(100, 100, 450, 300);
        contentPane = new JPanel();
        contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
        setContentPane(contentPane);
        contentPane.setLayout(null);

        textField = new JTextField();
        textField.setEditable(false);
        textField.setBounds(10, 11, 198, 20);
        contentPane.add(textField);
        textField.setColumns(10);

        JButton btnNewButton = new JButton("C");
        btnNewButton.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                textField.setText("");
            }
        });
        btnNewButton.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
            }
        });
        btnNewButton.setBounds(302, 10, 48, 23);
        contentPane.add(btnNewButton);

        JButton btnAc = new JButton("AC");
        btnAc.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                Calculator.a = (float) 0.0;
                Calculator.b = (float) 0.0;
                Calculator.b = 0;
                textField.setText("");

            }
        });
        btnAc.setBounds(360, 10, 64, 23);
        contentPane.add(btnAc);

        JButton btnNewButton_1 = new JButton("7");
        btnNewButton_1.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                textField.setText(textField.getText() + "7");
            }
        });
        btnNewButton_1.setFont(new Font("Tahoma", Font.PLAIN, 20));
        btnNewButton_1.setBounds(10, 42, 48, 48);
        contentPane.add(btnNewButton_1);

        JButton button = new JButton("8");
        button.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                textField.setText(textField.getText() + "8");
            }
        });
        button.setFont(new Font("Tahoma", Font.PLAIN, 20));
        button.setBounds(76, 42, 48, 48);
        contentPane.add(button);

        JButton button_1 = new JButton("9");
        button_1.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                textField.setText(textField.getText() + "9");
            }
        });
        button_1.setFont(new Font("Tahoma", Font.PLAIN, 20));
        button_1.setBounds(150, 42, 48, 48);
        contentPane.add(button_1);

        JButton button_2 = new JButton("6");
        button_2.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                textField.setText(textField.getText() + "6");
            }
        });
        button_2.setFont(new Font("Tahoma", Font.PLAIN, 20));
        button_2.setBounds(150, 101, 48, 48);
        contentPane.add(button_2);

        JButton button_3 = new JButton("5");
        button_3.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                textField.setText(textField.getText() + "5");
            }
        });
        button_3.setFont(new Font("Tahoma", Font.PLAIN, 20));
        button_3.setBounds(76, 101, 48, 48);
        contentPane.add(button_3);

        JButton button_4 = new JButton("4");
        button_4.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                textField.setText(textField.getText() + "4");
            }
        });
        button_4.setFont(new Font("Tahoma", Font.PLAIN, 20));
        button_4.setBounds(10, 101, 48, 48);
        contentPane.add(button_4);

        JButton button_5 = new JButton("3");
        button_5.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                textField.setText(textField.getText() + "3");
            }
        });
        button_5.setFont(new Font("Tahoma", Font.PLAIN, 20));
        button_5.setBounds(150, 160, 48, 48);
        contentPane.add(button_5);

        JButton button_6 = new JButton("2");
        button_6.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                textField.setText(textField.getText() + "2");
            }
        });
        button_6.setFont(new Font("Tahoma", Font.PLAIN, 20));
        button_6.setBounds(76, 160, 48, 48);
        contentPane.add(button_6);

        JButton button_7 = new JButton("1");
        button_7.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                textField.setText(textField.getText() + "1");
            }
        });
        button_7.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
            }
        });
        button_7.setFont(new Font("Tahoma", Font.PLAIN, 20));
        button_7.setBounds(10, 160, 48, 48);
        contentPane.add(button_7);

        JButton button_8 = new JButton("\u221A");
        button_8.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                Calculator.a = Float.parseFloat(textField.getText());
                Calculator.op = 6;
                textField.setText("");
            }
        });
        button_8.setFont(new Font("Tahoma", Font.PLAIN, 20));
        button_8.setBounds(333, 44, 66, 48);
        contentPane.add(button_8);

        JButton button_9 = new JButton("^");
        button_9.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                Calculator.a = Float.parseFloat(textField.getText());
                Calculator.op = 5;
                textField.setText("");
            }
        });
        button_9.setFont(new Font("Tahoma", Font.PLAIN, 20));
        button_9.setBounds(257, 44, 66, 48);
        contentPane.add(button_9);

        JButton button_10 = new JButton("/");
        button_10.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                Calculator.a = Float.parseFloat(textField.getText());
                Calculator.op = 4;
                textField.setText("");
            }
        });
        button_10.setFont(new Font("Tahoma", Font.PLAIN, 20));
        button_10.setBounds(333, 103, 66, 48);
        contentPane.add(button_10);

        JButton button_11 = new JButton("*");
        button_11.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                Calculator.a = Float.parseFloat(textField.getText());
                Calculator.op = 3;
                textField.setText("");
            }
        });
        button_11.setFont(new Font("Tahoma", Font.PLAIN, 20));
        button_11.setBounds(257, 103, 66, 48);
        contentPane.add(button_11);

        JButton button_12 = new JButton("-");
        button_12.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                Calculator.a = Float.parseFloat(textField.getText());
                Calculator.op = 2;
                textField.setText("");
            }
        });
        button_12.setFont(new Font("Tahoma", Font.PLAIN, 20));
        button_12.setBounds(333, 162, 66, 48);
        contentPane.add(button_12);

        JButton button_13 = new JButton("+");
        button_13.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                Calculator.a = Float.parseFloat(textField.getText());
                Calculator.op = 1;
                textField.setText("");
            }
        });
        button_13.setFont(new Font("Tahoma", Font.PLAIN, 20));
        button_13.setBounds(257, 162, 66, 48);
        contentPane.add(button_13);

        JButton btnNewButton_2 = new JButton("=");
        btnNewButton_2.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                if (Calculator.b == 0) {
                    Calculator.b = Float.parseFloat(textField.getText());
                }
                if (Calculator.op == 1) {
                    textField.setText(Float.toString(Calculator.a + Calculator.b));
                    Calculator.a = Calculator.a + Calculator.b;
                }
                if (Calculator.op == 2) {
                    textField.setText(Float.toString(Calculator.a - Calculator.b));
                    Calculator.a = Calculator.a - Calculator.b;
                }
                if (Calculator.op == 3) {
                    textField.setText(Float.toString(Calculator.a * Calculator.b));
                    Calculator.a = Calculator.a * Calculator.b;
                }
                if (Calculator.op == 4) {
                    textField.setText(Float.toString(Calculator.a / Calculator.b));
                    Calculator.a = Calculator.a / Calculator.b;
                }
                if (Calculator.op == 5) {
                    textField.setText(Float.toString((int) Math.pow(Calculator.a,
                            Calculator.b)));
                    Calculator.a = (int) Math.pow(Calculator.a, Calculator.b);
                }
                if (Calculator.op == 6) {
                    float h = 1 / Calculator.b;
                    textField.setText(Float.toString((float) Math.pow(Calculator.a,
                            h)));
                    Calculator.a = (float) Math.pow(Calculator.a, h);

                }
            }
        });
        btnNewButton_2.setBounds(257, 214, 142, 37);
        contentPane.add(btnNewButton_2);

        JButton btnDel = new JButton("DEL");
        btnDel.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                StringBuilder j = new StringBuilder();
                j.append(textField.getText());
                textField.setText(j.substring(0,
                        textField.getText().length() - 1));
            }
        });
        btnDel.setBounds(218, 10, 74, 23);
        contentPane.add(btnDel);

        JButton button_14 = new JButton("0");
        button_14.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {textField.setText(textField.getText() + "0");
            }
        });
        button_14.setFont(new Font("Tahoma", Font.PLAIN, 20));
        button_14.setBounds(76, 214, 48, 48);
        contentPane.add(button_14);

        JButton button_15 = new JButton(".");
        button_15.addMouseListener(new MouseAdapter() {
            @Override
            public void mouseClicked(MouseEvent e) {
                boolean g=true;
                String b=".";
                for(int a=0;a<textField.getText().length();a++){
                    if(textField.getText().charAt(a)==b.charAt(0)){g=false;}
                }
                if(g){
                textField.setText(textField.getText() + ".");}
            }
        });
        button_15.setFont(new Font("Tahoma", Font.PLAIN, 20));
        button_15.setBounds(10, 214, 48, 48);
        contentPane.add(button_15);
    }
}