while_loop

import java.util.Scanner;

public class whileLoop {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        // TODO: While loop to print numbers from 1 to 5
        int j = 1;
        while (j <= 5) {
            System.out.println(j);
            j++;
        }
/* ------------------------------------------------------- */
        // TODO: While loop to print even numbers from 2 to 10
        int i = 2;
        while (i <= 10) {
            System.out.println(i);
            i += 2;
        }
/* ------------------------------------------------------- */
        // TODO: While loop to calculate the sum of numbers from 1 to 100 (skip multiples of 5)
        int sum = 0;
        int k = 1;
        while (k <= 100) {
            if (k % 5 != 0) {
                sum += k;
            }
            k++;
        }
        System.out.println("Sum: " + sum);
/* ------------------------------------------------------- */
        // TODO: While loop to check if a number is prime
        System.out.print("Enter a number: ");
        int num = scanner.nextInt();

        boolean isPrime = true;
        int m = 2;
        while (m <= num / 2) {
            if (num % m == 0) {
                isPrime = false;
                break;
            }
            m++;
        }
        if (isPrime) {
            System.out.println(num + " is a prime number.");
        } else {
            System.out.println(num + " is not a prime number.");
        }
/* ------------------------------------------------------- */
        // TODO: While loop to find the factorial of a number
        System.out.print("Enter a number: ");
        int n = scanner.nextInt();

        int factorial = 1;
        int f = 1;
        while (f <= n) {
            factorial *= f;
            f++;
        }
        System.out.println("Factorial of " + n + ": " + factorial);
/* ------------------------------------------------------- */
        // TODO: While loop to reverse a number
        System.out.print("Enter a number: ");
        int num_f = scanner.nextInt();
        int reversedNum = 0;
        while (num_f != 0) {
            int digit = num_f % 10;
            reversedNum = reversedNum * 10 + digit;
            num_f /= 10;
        }
        System.out.println("Reversed number: " + reversedNum);
/* ------------------------------------------------------- */
        // TODO: Reading User Input Until a Valid Value is Entered
        int userInput = -1;
        while (userInput < 0 || userInput > 100) {
            System.out.print("Enter a number between 0 and 100: ");
            userInput = scanner.nextInt();

            if (userInput < 0 || userInput > 100) {
                System.out.println("Invalid input. Try again.");
            }
        }
        System.out.println("Valid input received: " + userInput);
        /* -------------------do while-------------------- */
        // TODO: Do-while loop to print numbers from 1 to 5
        int i2 = 1;
        do {
            System.out.println(i2);
            i2++;
        } while (i2 <= 5);
/* ------------------------------------------------------- */
        // TODO: Do-while loop to print even numbers from 2 to 10
        int i3 = 2;
        do {
            System.out.println(i3);
            i3 += 2;
        } while (i3 <= 10);
/* ------------------------------------------------------- */
        // TODO: User Input Validation with a do-while Loop
        int userInput_2;
        do {
            System.out.print("Enter a positive number: ");
            userInput_2 = scanner.nextInt();

            if (userInput_2 <= 0) {
                System.out.println("Invalid input. Please enter a positive number.");
            }
        } while (userInput_2 <= 0);
        System.out.println("Valid input received: " + userInput_2);
/* ------------------------------------------------------- */
        // TODO: Do-while loop to print a triangle of numbers
        System.out.print("Enter the number of rows for the triangle: ");
        int rows = scanner.nextInt();
        int h = 1;

        do {
            int jj = 1;
            do {
                System.out.print(jj + " ");
                jj++;
            } while (jj <= h);
            System.out.println();
            h++;
        } while (h <= rows);
/* ------------------------------------------------------- */
        // TODO:-----------------break and continue--------------------
        /*
        TODO: A user is withdrawing money from an ATM.
         The ATM has a withdrawal limit of $5000.
         If the user tries to withdraw more than that,
         the system stops the process immediately.
        */
        int withdrawalLimit = 5000;
        while (true) {
            System.out.print("Enter withdrawal amount: ");
            int amount = scanner.nextInt();
            if (amount > withdrawalLimit) {
                System.out.println("Error: Exceeds withdrawal limit! Transaction stopped.");
                break;
            }
            System.out.println("Withdrawal of $" + amount + " successful!");
        }
        System.out.println("ATM session ended.");
        scanner.close();
/* ------------------------------------------------------- */
        /*
        TODO: A company sends work reminders from Monday to
         Friday, but skips Saturday and Sunday.
        */
        int day = 1; // 1 = Monday, 7 = Sunday
        while (day <= 7) {
            if (day == 6 || day == 7) { // 6 = Saturday, 7 = Sunday
                System.out.println("Skipping: Day " + day + " (Weekend)");
                day++;
                continue; // Skip the weekend
            }
            System.out.println("Sending work reminder for Day " + day);
            day++;
        }
        System.out.println("Work schedule completed.");
    }
}