1. What is This Swing Calculator?

This is a simple calculator that performs basic arithmetic operations (addition, subtraction, multiplication, and division) between two numbers. The calculator is implemented using Java Swing for the graphical interface.

2. How Does the Calculator Work?

The calculator performs the selected operation on the two input numbers:

Where:

• \( num1 \) — First input number
• \( num2 \) — Second input number
• \( operation \) — One of: +, -, ×, ÷

3. Source Code Explanation

Java Swing Implementation:

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

public class SwingCalculator {
    public static void main(String[] args) {
        // Create frame
        JFrame frame = new JFrame("Swing Calculator");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(300, 400);
        
        // Create components
        JTextField num1Field = new JTextField(10);
        JTextField num2Field = new JTextField(10);
        JComboBox operationBox = new JComboBox<>(new String[]{"+", "-", "×", "÷"});
        JButton calculateButton = new JButton("Calculate");
        JLabel resultLabel = new JLabel("Result: ");
        
        // Layout
        JPanel panel = new JPanel(new GridLayout(5, 2));
        panel.add(new JLabel("First Number:"));
        panel.add(num1Field);
        panel.add(new JLabel("Second Number:"));
        panel.add(num2Field);
        panel.add(new JLabel("Operation:"));
        panel.add(operationBox);
        panel.add(calculateButton);
        panel.add(resultLabel);
        
        // Action listener
        calculateButton.addActionListener(e -> {
            try {
                double num1 = Double.parseDouble(num1Field.getText());
                double num2 = Double.parseDouble(num2Field.getText());
                String operation = (String) operationBox.getSelectedItem();
                double result = 0;
                
                switch (operation) {
                    case "+": result = num1 + num2; break;
                    case "-": result = num1 - num2; break;
                    case "×": result = num1 * num2; break;
                    case "÷": result = num1 / num2; break;
                }
                
                resultLabel.setText("Result: " + result);
            } catch (NumberFormatException ex) {
                resultLabel.setText("Invalid input!");
            }
        });
        
        frame.add(panel);
        frame.setVisible(true);
    }
}
                    

4. Using the Calculator

Instructions: Enter two numbers, select an operation, and click Calculate to see the result.

5. Frequently Asked Questions (FAQ)

Q1: What is Java Swing?
A: Swing is a GUI widget toolkit for Java that provides components like buttons, text fields, etc. for building graphical user interfaces.

Q2: How do I run this calculator?
A: Compile the Java code and run the class file, or use an IDE like Eclipse or IntelliJ IDEA.

Q3: Can I extend this calculator?
A: Yes, you can add more operations or features by modifying the source code.

Q4: What are the limitations?
A: This is a basic calculator. For scientific calculations, you would need to add more operations.

Q5: How does this compare to AWT?
A: Swing is more advanced than AWT, with better components and look-and-feel customization.