1. Write a program in Java to accept 10 integers into a one-dimensional array. Sort the array using Selection Sort and display the sorted array. answer

import java.util.Scanner;

public class SortArray { private int[] arr = new int[10];

// Method to accept values into the array
public void acceptValues() {
    Scanner sc = new Scanner(System.in);
    System.out.println("Enter 10 integers:");
    for (int i = 0; i < arr.length; i++) {
        arr[i] = sc.nextInt();
    }
}

// Method to perform selection sort
public void selectionSort() {
    int n = arr.length;
    for (int i = 0; i < n - 1; i++) {
        int minIndex = i;
        for (int j = i + 1; j < n; j++) {
            if (arr[j] < arr[minIndex]) {
                minIndex = j;
            }
        }
        // Swap the found minimum element with the first element
        int temp = arr[minIndex];
        arr[minIndex] = arr[i];
        arr[i] = temp;
    }
}

// Method to display the sorted array
public void displaySortedArray() {
    System.out.println("Sorted Array in Ascending Order:");
    for (int i : arr) {
        System.out.print(i + " ");
    }
    System.out.println();
}

public static void main(String[] args) {
    SortArray obj = new SortArray();
    obj.acceptValues();
    obj.selectionSort();
    obj.displaySortedArray();
}

}

2. Write a Java program to accept 9 integers Into a 3x3 array. Check whether the array is a special array where the sum of diagonal elements is equal to the sum of the non-diagonal elements. answer import java.util.Scanner;

public class SpecialArray { private int[][] arr = new int[3][3];

// Method to accept values into the array
public void acceptValues() {
    Scanner sc = new Scanner(System.in);
    System.out.println("Enter 9 integers for a 3x3 array:");
    for (int i = 0; i < 3; i++) {
        for (int j = 0; j < 3; j++) {
            arr[i][j] = sc.nextInt();
        }
    }
}

// Method to check if it is a special array
public void checkSpecialArray() {
    int diagonalSum = arr[0][0] + arr[1][1] + arr[2][2];
    int totalSum = 0;
    for (int i = 0; i < 3; i++) {
        for (int j = 0; j < 3; j++) {
            totalSum += arr[i][j];
        }
    }

    if (diagonalSum == (totalSum - diagonalSum)) {
        System.out.println("It is a special array.");
    } else {
        System.out.println("It is not a special array.");
    }
}

public static void main(String[] args) {
    SpecialArray obj = new SpecialArray();
    obj.acceptValues();
    obj.checkSpecialArray();
}

}

3. Design a class Student in Java to store the name, age, marks, and stream of a student. Implement methods to accept and display the student details. answer import java.util.Scanner;

public class Student { // Data members String name; int age; int marks; String stream;

// Method to accept data
public void acceptData() {
    Scanner sc = new Scanner(System.in);
    System.out.print("Enter name: ");
    name = sc.nextLine();
    System.out.print("Enter age: ");
    age = sc.nextInt();
    System.out.print("Enter marks: ");
    marks = sc.nextInt();
    sc.nextLine();  // Consume newline
    System.out.print("Enter stream: ");
    stream = sc.nextLine();
}

// Method to display data
public void displayData() {
    System.out.println("Name: " + name);
    System.out.println("Age: " + age);
    System.out.println("Marks: " + marks);
    System.out.println("Stream: " + stream);
}

public static void main(String[] args) {
    Student student = new Student();
    student.acceptData();
    student.displayData();
}

}

4. Write a Java program to accept 25 integers into an array. Input a value from the user and search for the value in the array, displaying its position. If the value is not found, display an appropriate message. answer import java.util.Scanner;

public class SearchValue { private int[] arr = new int[25];

// Method to accept values into the array
public void acceptValues() {
    Scanner sc = new Scanner(System.in);
    System.out.println("Enter 25 integers:");
    for (int i = 0; i < arr.length; i++) {
        arr[i] = sc.nextInt();
    }
}

// Method to search for a value and display position
public void searchValue(int key) {
    boolean found = false;
    for (int i = 0; i < arr.length; i++) {
        if (arr[i] == key) {
            System.out.println("Found " + key + " at position: " + (i + 1));
            found = true;
            break;
        }
    }
    if (!found) {
        System.out.println("Value not found in the array.");
    }
}

public static void main(String[] args) {
    SearchValue obj = new SearchValue();
    obj.acceptValues();
    Scanner sc = new Scanner(System.in);
    System.out.print("Enter the value to search: ");
    int key = sc.nextInt();
    obj.searchValue(key);
}

}

5. Write a Java program to:

• Print Floyd's Triangle for a given number of rows.

• Display the following pattern for a given number of rows:

  I I I C S E I I I C S E

answer import java.util.Scanner;

public class Patterns { // Method to print Floyd's Triangle public void floydsTriangle(int n) { int num = 1; for (int i = 1; i <= n; i++) { for (int j = 1; j <= i; j++) { System.out.print(num + " "); num++; } System.out.println(); } }

// Method to display the pattern
public void displayPattern(int n) {
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= i; j++) {
            System.out.print("I ");
        }
        System.out.println("C S E");
    }
}

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    Patterns obj = new Patterns();

    System.out.println("Menu:");
    System.out.println("1. Print Floyd's Triangle");
    System.out.println("2. Display Pattern");
    System.out.print("Enter your choice: ");
    int choice = sc.nextInt();

    switch (choice) {
        case 1:
            System.out.print("Enter the number of rows: ");
            int rows = sc.nextInt();
            obj.floydsTriangle(rows);
            break;

        case 2:
            System.out.print("Enter the number of rows for the pattern: ");
            int n = sc.nextInt();
            obj.displayPattern(n);
            break;

        default:
            System.out.println("Invalid choice.");
    }
}

}

6. Write a Java program to accept a country name from the user and display the corresponding Wonder of the World from a predefined list. If the country is not in the list, display an appropriate message. answer import java.util.Scanner;

public class SevenWonders { // List of wonders and corresponding countries String[] wonders = {"CHRIST THE REDEEMER", "TAJ MAHAL", "GREAT WALL OF CHINA", "MACHU PICCHU", "PETRA", "COLOSSEUM"}; String[] countries = {"BRAZIL", "INDIA", "CHINA", "PERU", "JORDAN", "ITALY"};

// Method to find the wonder by country
public void findWonder(String country) {
    boolean found = false;
    for (int i = 0; i < countries.length; i++) {
        if (countries[i].equalsIgnoreCase(country)) {
            System.out.println("Wonder: " + wonders[i] + ", Country: " + countries[i]);
            found = true;
            break;
        }
    }
    if (!found) {
        System.out.println("Sorry, wonder not found for the given country.");
    }
}

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    SevenWonders obj = new SevenWonders();
    System.out.print("Enter a country name: ");
    String country = sc.nextLine();
    obj.findWonder(country);
}

}

7. Design a class Movie in Java with attributes year, title, and rating. Implement methods to accept and display movie details. answerimport java.util.Scanner;

public class Movie { int year; String title; double rating;

// Default constructor
public Movie() {
    year = 0;
    title = "";
    rating = 0.0;
}

// Method to accept movie details
public void acceptDetails() {
    Scanner sc = new Scanner(System.in);
    System.out.print("Enter movie title: ");
    title = sc.nextLine();
    System.out.print("Enter year of release: ");
    year = sc.nextInt();
    System.out.print("Enter movie rating (1.0 to 5.0): ");
    rating = sc.nextDouble();
}

// Method to display movie details
public void displayDetails() {
    System.out.println("Movie Title: " + title);
    System.out.println("Year of Release: " + year);
    System.out.println("Rating: " + rating);
}

public static void main(String[] args) {
    Movie obj = new Movie();
    obj.acceptDetails();
    obj.displayDetails();
}

}

8. Write a Java program to accept the name and salary of 3 employees. Display the details of the employee with the highest salary. answer import java.util.Scanner;

public class Employee { String name; int salary;

// Default constructor
public Employee() {
    name = "";
    salary = 0;
}

// Method to accept employee details
public void acceptDetails() {
    Scanner sc = new Scanner(System.in);
    System.out.print("Enter employee name: ");
    name = sc.nextLine();
    System.out.print("Enter employee salary: ");
    salary = sc.nextInt();
}

// Method to find the employee with the highest salary
public static void findHighest(Employee[] empArray) {
    Employee highest = empArray[0];
    for (Employee emp : empArray) {
        if (emp.salary > highest.salary) {
            highest = emp;
        }
    }
    System.out.println("Employee with the highest salary: " + highest.name + " (" + highest.salary + ")");
}

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    Employee[] employees = new Employee[3];

    // Accepting details of 3 employees
    for (int i = 0; i < employees.length; i++) {
        employees[i] = new Employee();
        System.out.println("Enter details for employee " + (i + 1) + ":");
        employees[i].acceptDetails();
    }

    // Find and display the employee with the highest salary
    findHighest(employees);
}

}

9. The weekly hours of all employees of ABC Consulting Ltd. are stored in a two-dimensional array. Each row records an employee's 7-day work hours with seven columns. For example, the following array stores the work hours of five employees. Write a program that displays employees and their total hours in decreasing order of the total hours.

public class EmployeeHours { public static void main(String[] args) { int[][] hours = { {8, 5, 1, 11, 1, 0, 0}, // Employee 0 {11, 6, 0, 2, 2, 2, 4}, // Employee 1 {4, 5, 4, 10, 4, 3, 1}, // Employee 2 {4, 7, 3, 12, 6, 2, 0}, // Employee 3 {3, 8, 3, 2, 4, 4, 0} // Employee 4 };

    int[][] totalHours = new int[hours.length][2];
    
    // Calculate total hours for each employee
    for (int i = 0; i < hours.length; i++) {
        int sum = 0;
        for (int j = 0; j < hours[i].length; j++) {
            sum += hours[i][j];
        }
        totalHours[i][0] = i;   // Employee number
        totalHours[i][1] = sum; // Total hours
    }

    // Sort by total hours in decreasing order
    Arrays.sort(totalHours, (a, b) -> Integer.compare(b[1], a[1]));

    // Display employees and their total hours
    System.out.println("Employee\tTotal Hours");
    for (int i = 0; i < totalHours.length; i++) {
        System.out.println("Employee " + totalHours[i][0] + "\t\t" + totalHours[i][1]);
    }
}

}

10. Write a program that reads a 4 x 5 two-dimensional array and then prints the column sums of the array along with the array printed in matrix form. answer import java.util.Scanner;

public class MatrixColumnSum { public static void main(String[] args) { Scanner sc = new Scanner(System.in); int[][] matrix = new int[4][5];

    // Reading the matrix
    System.out.println("Enter the elements of the 4x5 matrix:");
    for (int i = 0; i < 4; i++) {
        for (int j = 0; j < 5; j++) {
            matrix[i][j] = sc.nextInt();
        }
    }

    // Printing the matrix
    System.out.println("Matrix:");
    for (int i = 0; i < 4; i++) {
        for (int j = 0; j < 5; j++) {
            System.out.print(matrix[i][j] + "\t");
        }
        System.out.println();
    }

    // Calculating and printing column sums
    System.out.println("Column sums:");
    for (int j = 0; j < 5; j++) {
        int sum = 0;
        for (int i = 0; i < 4; i++) {
            sum += matrix[i][j];
        }
        System.out.println("Column " + (j + 1) + ": " + sum);
    }
}

}

11. A palindromic prime is a prime number and also palindromic. For example, 131, 313, and 757 are prime numbers and also palindromic prime numbers. Write a program that displays the first 100 palindromic prime numbers. answer public class PalindromicPrime { public static boolean isPrime(int num) { if (num < 2) return false; for (int i = 2; i <= Math.sqrt(num); i++) { if (num % i == 0) return false; } return true; }

public static boolean isPalindrome(int num) {
    String str = Integer.toString(num);
    return str.equals(new StringBuilder(str).reverse().toString());
}

public static void main(String[] args) {
    int count = 0;
    int num = 2;

    System.out.println("First 100 Palindromic Prime Numbers:");
    while (count < 100) {
        if (isPrime(num) && isPalindrome(num)) {
            System.out.print(num + " ");
            count++;
        }
        num++;
    }
}

}

12. Write a program in Java to read a number, remove all zeros from it, and display the new number. For example:

Sample Input: 45407703
Sample Output: 454773 answer import java.util.Scanner;

public class RemoveZeros { public static void main(String[] args) { Scanner sc = new Scanner(System.in); System.out.print("Enter a number: "); String number = sc.nextLine();

    String result = number.replace("0", "");
    System.out.println("New number: " + result);
}

}

13. Define a class to accept values in an integer array of size 10 and perform a binary search on it. answer import java.util.Arrays; import java.util.Scanner;

public class BinarySearchArray { public static int binarySearch(int[] arr, int key) { int low = 0, high = arr.length - 1; while (low <= high) { int mid = (low + high) / 2; if (arr[mid] == key) return mid; else if (arr[mid] < key) low = mid + 1; else high = mid - 1; } return -1; }

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int[] arr = new int[10];

    // Accept array values
    System.out.println("Enter 10 integers:");
    for (int i = 0; i < arr.length; i++) {
        arr[i] = sc.nextInt();
    }

    // Sort the array
    Arrays.sort(arr);

    // Search for a number
    System.out.print("Enter the number to search: ");
    int key = sc.nextInt();
    int index = binarySearch(arr, key);

    if (index != -1) {
        System.out.println("Number found at position: " + (index + 1));
    } else {
        System.out.println("Number not found.");
    }
}

}

14. Write a program to input a sentence and convert it into uppercase and count and display the total number of words starting with the letter 'A'.

Example:
Sample Input: ADVANCEMENT AND APPLICATION OF INFORMATION TECHNOLOGY ARE EVER CHANGING.
Sample Output: Total number of words starting with letter 'A' = 4. answer import java.util.Scanner;

public class CountWordsWithA { public static void main(String[] args) { Scanner sc = new Scanner(System.in); System.out.print("Enter a sentence: "); String sentence = sc.nextLine().toUpperCase();

    String[] words = sentence.split(" ");
    int count = 0;
    
    for (String word : words) {
        if (word.startsWith("A")) {
            count++;
        }
    }

    System.out.println("Total number of words starting with 'A': " + count);
}

}

15. Define a class to accept values in an integer array of size 10. Sort them in ascending order using the bubble sort technique. Display the sorted array. answer import java.util.Scanner;

public class BubbleSortArray { public static void bubbleSort(int[] arr) { int n = arr.length; for (int i = 0; i < n - 1; i++) { for (int j = 0; j < n - i - 1; j++) { if (arr[j] > arr[j + 1]) { // Swap arr[j] and arr[j+1] int temp = arr[j]; arr[j] = arr[j + 1]; arr[j + 1] = temp; } } } }

public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    int[] arr = new int[10];

    // Accept array values
    System.out.println("Enter 10 integers:");
    for (int i = 0; i < arr.length; i++) {
        arr[i] = sc.nextInt();
    }

    // Sort the array
    bubbleSort(arr);

    // Display sorted array
    System.out.println("Sorted array:");
    for (int i : arr) {
        System.out.print(i + " ");
    }
}

}