📚 Java Quiz Application (Console-Based)

🧠 Overview

The Quiz Application is a Java-based console program designed to offer a complete quiz-taking and management experience for both users and administrators. The system supports registration, login, timed quizzes of various difficulty levels, and full admin-level quiz control. All data is file-based, making it easy to run without a database setup.

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🎯 Features

👤 User Features:

• Secure Registration with age validation (15+).
• Strong Password Enforcement (8+ characters, 1 uppercase, 1 digit, 1 special character).
• Multiple Difficulty Levels: Easy, Medium, Hard, and Surprise.
• Timed Quizzes with countdown display (different times per level).
• Personal Result History: View your own quiz performance.

🛠️ Admin Features:

• Admin Login with credential validation.
• Add Quizzes by subject and difficulty.
• Edit Quizzes to append questions.
• Delete Quizzes and update the system.
• View All Users' Results from one file.

💻 Technical Features:

• File-Based Storage (no external database needed).
• Input Validation on usernames, passwords, and age.
• Quiz Engine with randomization support and timer functionality.

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🧩 System Modules

1. User Authentication Module

• Registration: Inputs username, age, and password; checks password strength and age.
• Login: Authenticates users from registrations.txt, allows 3 attempts.

2. Quiz Module

• Difficulty Selector: Lets users pick Easy, Medium, Hard, or Surprise.
• Question Loading: Reads from subject/difficulty-specific files.
• Timed Quiz: Each level has a different time (e.g., Easy: 2.5 mins).
• Answer Check & Score Display: Evaluates user responses in real time.

3. Admin Module

• Add Quiz: Creates quiz and key files per difficulty level.
• Edit Quiz: Adds new questions to existing quiz files.
• Delete Quiz: Deletes quiz + key files and updates Subjects.txt.

4. Result Tracking Module

• User Results: Saved in [Username].txt.
• Admin Results: All attempts saved in AllResults.txt.

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🗂️ File Structure

File Name	Purpose	Format/Example
registrations.txt	User login info	johnDoe|Pass123!|20
adminlogin.txt	Admin credentials	admin|Admin@123
Subjects.txt	Lists subjects	1: Math
[Subject][Difficulty]Quiz.txt	Quiz questions	What is 2+2?$A. 3$B. 4$C. 5$D. 6
[Subject][Difficulty]Key.txt	Answer keys	B
AllResults.txt	Records of all quiz attempts	johnDoe scored 4/5 in MathEasy
[Username].txt	Individual user result history	Previous attempts by johnDoe
SurpriseQuiz.txt / SurpriseKey.txt	Randomized questions and keys	Same format as others

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🔧 Key Methods

Method	Purpose
isStrong(String password)	Validates password complexity.
duplicateUsers(String userName)	Checks if username already exists.
duplicateUsers(String userName, String password)	Checks user credentials.
registerUser()	Handles registration with validation.
loginUser()	Handles login with 3 attempts max.
loginAdmin()	Admin login logic.
difficultyLevel()	Lets users choose difficulty.
startQuiz()	Manages quiz process and flow.
takeQuiz(...)	Loads questions, runs timer, checks answers, saves results.
viewResults()	Shows personal quiz results.
viewAllResults()	Admin-only method to view all user results.
addQuiz()	Creates new quiz and key files.
editQuiz()	Appends questions to existing quizzes.
deleteQuiz()	Deletes quiz files and updates subject list.
lineCounter(String file)	Helper to count number of questions in a file.
createFile(...)	Creates quiz + key files and updates Subjects.txt.
deleteFile(...)	Deletes quiz + key files and updates Subjects.txt.

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📌 Requirements

• Java SE (Standard Edition)
• Any IDE: NetBeans, Eclipse, IntelliJ, or plain terminal
• No external libraries required
• Runs via console

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🚀 How to Run

1. Clone or download the project files.
2. Open in your preferred IDE or compile via command line.
3. Run the main class.
4. Choose between User or Admin mode.
5. Follow the prompts for registration, login, quiz-taking, or quiz management.

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📎 License

This project is open for educational use and modification.