🧮 Smart Calculator Web App

A modern, responsive calculator built using HTML, CSS, and JavaScript with smart input handling and clean UI.

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🚀 Features

• ➕ Basic arithmetic operations (+, −, ×, ÷)
• ⚡ Real-time calculation
• 🧠 Smart input validation (prevents invalid expressions)
• 🎯 Handles negative numbers correctly
• ❌ Prevents multiple operators (like ++, **, etc.)
• 🖥️ Responsive design (works on desktop & mobile)
• 🎨 Clean and minimal UI

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🛠️ Tech Stack

• Frontend: HTML, CSS, JavaScript
• Logic: Vanilla JavaScript (no libraries)

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📂 Project Structure

calculator-project/
│── index.html
│── style.css
│── app.js
│── README.md
|__ images/Smart Calculator Web App.png

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📸 Project Preview

⚙️ How It Works

• Captures user input via buttons
• Builds a mathematical expression as a string
• Validates input to avoid invalid operations
• Uses eval() (or custom logic) to compute results
• Displays output dynamically on screen

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🧠 Smart Logic Example

// Prevent double operators
if (["+", "-", "*", "/"].includes(value)) {
    if (expression === "" || ["+", "-", "*", "/"].includes(lastChar)) {
        return;
    }
}

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▶️ Run Locally

1. Clone the repository

git clone https://github.com/YOUR_USERNAME/calculator-project.git

2. Open the project

cd calculator-project

3. Run in browser Just open index.html

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🔥 Future Improvements

• 🧮 Scientific calculator mode
• 🌙 Dark / Light theme toggle
• ⌨️ Keyboard input support
• 📜 Calculation history
• 🧠 Replace eval() with safer parser

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🤝 Contributing

Contributions are welcome! Feel free to fork the repo and submit a pull request.

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📜 License

This project is open-source and available under the MIT License.

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⭐ If you like this project, give it a star!