🎓 Grade Calculator System

A menu-driven Grade Calculator application built using Java and OOP principles.
This project allows users to add student marks, calculate grades, view results, and analyze class performance with detailed statistics.

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✨ Features

• ➕ Add student details (name & marks)
• 👀 View all student results
• 📊 View class statistics
  • Average marks
  • Pass percentage
  • Top scorer
  • Grade-wise count
• 🧱 Fully Object-Oriented design
• 📦 Package-based project structure
• ⚠️ Exception handling for invalid inputs
• 🔁 Loop-based menu-driven UI

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📦 Project Structure

com.gradecalculator
│
├── model
│ └── Student.java
│
├── service
│ └── GradeCalculator.java
│
├── app
│ └── GradeCalculatorApp.java

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📌 Grading Criteria

Marks Range	Grade
90 – 100	A+
80 – 89	A
70 – 79	B
60 – 69	C
50 – 59	D
Below 50	F

Pass Marks: 50 and above

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🧠 Concepts Used

• Java OOP (Classes, Objects, Encapsulation)
• Menu-driven program
• ArrayList for storing students
• HashMap for grade-wise count
• Loops & conditional statements
• Exception handling (try-catch)
• Packages & modular design

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▶️ How to Run

1. Clone the repository
2. Open the project in any Java IDE (IntelliJ / Eclipse / VS Code)
3. Run GradeCalculatorApp.java
4. Use the menu to interact with the system

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🚀 Possible Enhancements

• Save student results to a file (CSV / TXT)
• Menu option to delete or update students
• Multi-subject support
• JUnit test cases
• GUI version (JavaFX / Swing)