1

SimpleCalculator.java

@@ -0,0 +1,105 @@
+import javax.swing.*;
+import java.awt.*;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+
+public class SimpleCalculator extends JFrame {
+
+    private JTextField display;
+    private JPanel panel;
+    private double operand1 = 0;
+    private double operand2 = 0;
+    private char operator;
+    private boolean userIsTypingSecondNumber = false;
+
+    public SimpleCalculator() {
+        setTitle("Simple Calculator");
+        setSize(400, 500);
+        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+        setLocationRelativeTo(null);
+
+        // Display text field
+        display = new JTextField();
+        display.setEditable(false);
+        display.setHorizontalAlignment(SwingConstants.RIGHT);
+        add(display, BorderLayout.NORTH);
+
+        // Panel for buttons
+        panel = new JPanel();
+        panel.setLayout(new GridLayout(5, 4, 10, 10));
+
+        // Add numbers and operations to panel
+        String[] buttons = {
+                "7", "8", "9", "/",
+                "4", "5", "6", "*",
+                "1", "2", "3", "-",
+                "0", ".", "=", "+",
+                "C"
+        };
+
+        for (String text : buttons) {
+            JButton button = new JButton(text);
+            button.setFont(new Font("Verdana", Font.PLAIN, 24));
+            button.setFocusable(false);
+            panel.add(button);
+            button.addActionListener(new ButtonClickListener());
+        }
+
+        add(panel, BorderLayout.CENTER);
+    }
+
+    private class ButtonClickListener implements ActionListener {
+        @Override
+        public void actionPerformed(ActionEvent e) {
+            String command = e.getActionCommand();
+
+            if ("0123456789.".contains(command)) {
+                display.setText(display.getText().concat(command));
+            } else if ("+-*/".contains(command)) {
+                operand1 = Double.parseDouble(display.getText());
+                operator = command.charAt(0);
+                userIsTypingSecondNumber = true;
+                display.setText(""); // Clear the display for the next number
+            } else if (command.equals("=")) {
+                if (userIsTypingSecondNumber) {
+                    operand2 = Double.parseDouble(display.getText());
+                    double result = 0;
+                    switch (operator) {
+                        case '+':
+                            result = operand1 + operand2;
+                            break;
+                        case '-':
+                            result = operand1 - operand2;
+                            break;
+                        case '*':
+                            result = operand1 * operand2;
+                            break;
+                        case '/':
+                            if (operand2 != 0) {
+                                result = operand1 / operand2;
+                            } else {
+                                display.setText("Error");
+                                return;
+                            }
+                            break;
+                    }
+                    display.setText(String.valueOf(result));
+                    operand1 = result; // Store the result for possible chain operations
+                    userIsTypingSecondNumber = false; // Reset for next operation
+                }
+            } else if (command.equals("C")) {
+                display.setText("");
+                operand1 = 0;
+                operand2 = 0;
+                userIsTypingSecondNumber = false;
+            }
+        }
+    }
+
+    public static void main(String[] args) {
+        SwingUtilities.invokeLater(() -> {
+            SimpleCalculator calculator = new SimpleCalculator();
+            calculator.setVisible(true);
+        });
+    }
+}