// ================================================================

// StudentUtilityApp.java

// ---------------------------------------------------------------

// Author: Agnibesh Maity

// Description:

// A complete beginner-friendly Java program that demonstrates

// multiple basic programming concepts in one place.

// It allows the user to:

// 1. Calculate Sum of Numbers

// 2. Check Even or Odd

// 3. Find Factorial

// 4. Generate Fibonacci Series

// 5. Display Simple Student Info

// ---------------------------------------------------------------

// Version: 1.0

// Created: October 2025

// ================================================================

import java.util.Scanner;

public class StudentUtilityApp {

// ------------------------------------------------------------

// 1. Sum of two numbers

// ------------------------------------------------------------

public static void sumOfNumbers(Scanner sc) {

System.out.println("\n--- SUM OF TWO NUMBERS ---");

System.out.print("Enter first number: ");

int a = sc.nextInt();

System.out.print("Enter second number: ");

int b = sc.nextInt();

System.out.println("✅ The sum is: " + (a + b));

}

// ------------------------------------------------------------

// 2. Check Even or Odd

// ------------------------------------------------------------

public static void checkEvenOdd(Scanner sc) {

System.out.println("\n--- EVEN OR ODD CHECKER ---");

System.out.print("Enter a number: ");

int num = sc.nextInt();

if (num % 2 == 0)

System.out.println("✅ " + num + " is Even.");

else

System.out.println("✅ " + num + " is Odd.");

}

// ------------------------------------------------------------

// 3. Factorial Calculator

// ------------------------------------------------------------

public static void factorialCalculator(Scanner sc) {

System.out.println("\n--- FACTORIAL CALCULATOR ---");

System.out.print("Enter a number: ");

int n = sc.nextInt();

long fact = 1;

for (int i = 1; i <= n; i++)

fact *= i;

System.out.println("✅ Factorial of " + n + " = " + fact);

}

// ------------------------------------------------------------

// 4. Fibonacci Series Generator

// ------------------------------------------------------------

public static void fibonacciSeries(Scanner sc) {

System.out.println("\n--- FIBONACCI SERIES GENERATOR ---");

System.out.print("Enter number of terms: ");

int n = sc.nextInt();

int a = 0, b = 1, c;

System.out.print("📘 Fibonacci Series: ");

for (int i = 1; i <= n; i++) {

System.out.print(a + " ");

c = a + b;

a = b;

b = c;

}

System.out.println();

}

// ------------------------------------------------------------

// 5. Display Student Information

// ------------------------------------------------------------

public static void studentInfo(Scanner sc) {

sc.nextLine(); // consume newline

System.out.println("\n--- STUDENT INFORMATION ---");

System.out.print("Enter your name: ");

String name = sc.nextLine();

System.out.print("Enter your department: ");

String dept = sc.nextLine();

System.out.print("Enter your roll number: ");

String roll = sc.nextLine();

System.out.println("\n🎓 STUDENT PROFILE 🎓");

System.out.println("--------------------------");

System.out.println("Name: " + name);

System.out.println("Department: " + dept);

System.out.println("Roll No.: " + roll);

System.out.println("--------------------------");

System.out.println("✨ Welcome, " + name + "! Keep learning and growing.");

}

// ------------------------------------------------------------

// Main Menu

// ------------------------------------------------------------

public static void mainMenu() {

Scanner sc = new Scanner(System.in);

int choice;

do {

System.out.println("\n==============================================");

System.out.println("🎯 STUDENT UTILITY APP - MULTI PURPOSE TOOL 🎯");

System.out.println("==============================================");

System.out.println("1️⃣ Calculate Sum of Two Numbers");

System.out.println("2️⃣ Check Even or Odd");

System.out.println("3️⃣ Find Factorial");

System.out.println("4️⃣ Generate Fibonacci Series");

System.out.println("5️⃣ Display Student Information");

System.out.println("6️⃣ Exit");

System.out.println("----------------------------------------------");

System.out.print("Enter your choice (1-6): ");

choice = sc.nextInt();

switch (choice) {

case 1 -> sumOfNumbers(sc);

case 2 -> checkEvenOdd(sc);

case 3 -> factorialCalculator(sc);

case 4 -> fibonacciSeries(sc);

case 5 -> studentInfo(sc);

case 6 -> System.out.println("\n👋 Exiting... Thank you for using StudentUtilityApp!");

default -> System.out.println("\n⚠️ Invalid choice! Please try again.");

}

} while (choice != 6);

sc.close();

}

// ------------------------------------------------------------

// Program Entry Point

// ------------------------------------------------------------

public static void main(String[] args) {

mainMenu();

}

}