Program 1. Write a program to execute arithmetic operations in java.
import java.util.Scanner;
public class ArithmeticOperations {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter first number: ");
double num1 = sc.nextDouble();
System.out.print("Enter second number: ");
double num2 = sc.nextDouble();
double sum = num1 + num2;
double difference = num1 - num2;
double product = num1 * num2;
double quotient = num1 / num2;
System.out.println("Sum: " + sum);
System.out.println("Difference: " + difference);
System.out.println("Product: " + product);
System.out.println("Quotient: " + quotient);
}
}
OUTPUT:
Program 2. Write a program to find the largest number.
import java.util.Scanner;
public class LargestNumber {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter first number: ");
int num1 = sc.nextInt();
System.out.print("Enter second number: ");
int num2 = sc.nextInt();
System.out.print("Enter third number: ");
int num3 = sc.nextInt();
int largest = (num1 > num2) ? (num1 > num3 ? num1 : num3) : (num2 > num3 ? num2 :
num3);
System.out.println("Largest number: " + largest);
OUTPUT:
Program 3. Write a program to check number is prime or not.
import java.util.Scanner;
public class PrimeCheck {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter a number: ");
int num = sc.nextInt();
sc.close();
boolean isPrime = true;
if (num <= 1) {
isPrime = false;
} else {
for (int i = 2; i <= Math.sqrt(num); i++) {
if (num % i == 0) {
isPrime = false;
break;
if (isPrime) {
System.out.println(num + " is a prime number.");
} else {
System.out.println(num + " is not a prime number.");
OUTPUT:
Program 4.write a program to check number is even or odd.
import java.util.Scanner;
public class EvenOdd {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter a number: ");
int num = sc.nextInt();
sc.close();
if (num % 2 == 0) {
System.out.println(num + " is even.");
} else {
System.out.println(num + " is odd.");
OUTPUT:
Program 5. Write a program to find the factorial of a number.
import java.util.Scanner;
public class Factorial {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter a number: ");
int num = sc.nextInt();
sc.close();
long factorial = 1;
for (int i = 1; i <= num; i++) {
factorial *= i;
System.out.println("Factorial of " + num + " is " + factorial);
OUTPUT:
Program 6. Write a program to find the reverse of a number.
import java.util.Scanner;
public class ReverseNumber {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter a number: ");
int num = sc.nextInt();
sc.close();
int reverse = 0;
while (num != 0) {
int digit = num % 10;
reverse = reverse * 10 + digit;
num /= 10;
System.out.println("Reversed number: " + reverse);
OUTPUT:
Program 7. Write a program to concatenate two strings.
import java.util.Scanner;
public class StringConcatenation {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter first string: ");
String str1 = sc.nextLine();
System.out.print("Enter second string: ");
String str2 = sc.nextLine();
sc.close();
String result = str1 + str2;
System.out.println("Concatenated string: " + result);
OUTPUT:
Program 8. Write a program to count number of char in a string.
import java.util.Scanner;
public class CharacterCount {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter a string: ");
String str = sc.nextLine();
sc.close();
int count = 0;
for (int i = 0; i < str.length(); i++) {
if (Character.isLetter(str.charAt(i))) {
count++;
System.out.println("Number of characters: " + count);
OUTPUT:
Program 9. Write a program to count number of vowels and consonants in a string.
import java.util.Scanner;
public class VowelConsonantCount {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter a string: ");
String str = sc.nextLine();
sc.close();
int vowels = 0, consonants = 0;
str = str.toLowerCase();
for (int i = 0; i < str.length(); i++) {
char ch = str.charAt(i);
if (ch >= 'a' && ch <= 'z') {
if (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u') {
vowels++;
} else {
consonants++;
System.out.println("Number of vowels: " + vowels);
System.out.println("Number of consonants: " + consonants);
OUTPUT:
Program 10. Write a program to reverse a string.
public class Reverse{
public static void main(String[] args) {
String str = "Hello, World!";
String reversed = "";
for (int i = str.length() - 1; i >= 0; i--) {
reversed += str.charAt(i);
System.out.println(reversed);
OUTPUT:
Program 11. Write a program to create an array.
public class ArrayExample {
public static void main(String[] args) {
int[] numbers = {1, 2, 3, 4, 5};
for (int i = 0; i < numbers.length; i++) {
System.out.println(numbers[i]);
OUTPUT:
Program 12. Write a program to make a left triangle star pattern.
public class StarPattern {
public static void main(String[] args) {
int rows = 5;
for (int i = 1; i <= rows; i++) {
for (int j = 1; j <= i; j++) {
System.out.print("*");
System.out.println();
OUTPUT:
Program 13. Write a program to print a number pattern in pyramid.
public class NumberPyramid {
public static void main(String[] args) {
int rows = 5;
for (int i = 1; i <= rows; i++) {
for (int j = rows; j > i; j--) {
System.out.print(" ");
for (int k = 1; k <= i; k++) {
System.out.print(k + " ");
System.out.println();
OUTPUT:
Program 14. Write a program to calculate the area of a rectangle using inner class.
public class Rectangle {
private double length;
private double width;
public Rectangle(double length, double width) {
this.length = length;
this.width = width;
public class Area {
public double calculateArea() {
return length * width;
public static void main(String[] args) {
Rectangle rectangle = new Rectangle(5.0, 3.0);
Rectangle.Area area = rectangle.new Area();
System.out.println("Area of the rectangle: " + area.calculateArea());
OUTPUT:
Program 15(a). Write a program to perform a multilevel inheritance.
class Animal {
void eat() {
System.out.println("This animal eats food.");
class Dog extends Animal {
void bark() {
System.out.println("The dog barks.");
class Puppy extends Dog {
void sleep() {
System.out.println("The puppy sleeps.");
public class MultilevelInheritance {
public static void main(String[] args) {
Puppy puppy = new Puppy();
puppy.eat();
puppy.bark();
puppy.sleep();
OUTPUT:
Program 15(b).Write a program to perform a hierarchical inheritance.
class Animal {
void eat() {
System.out.println("This animal eats food.");
class Dog extends Animal {
void bark() {
System.out.println("The dog barks.");
class Cat extends Animal {
void meow() {
System.out.println("The cat meows.");
public class HierarchicalInheritance {
public static void main(String[] args) {
Dog dog = new Dog();
dog.eat();
dog.bark();
Cat cat = new Cat();
cat.eat();
cat.meow();
}
OUTPUT:
Program 15(c). Write a program to perform multiple inheritance using interface.
interface Animal {
void eat();
interface Vehicle {
void drive();
class Dog implements Animal, Vehicle {
public void eat() {
System.out.println("The dog eats food.");
public void drive() {
System.out.println("The dog drives a vehicle.");
public class MultipleInheritanceUsingInterface {
public static void main(String[] args) {
Dog dog = new Dog();
dog.eat();
dog.drive();
OUTPUT:
Program 16. Write a program to implement method overloading.
class Calculator {
int add(int a, int b) {
return a + b;
int add(int a, int b, int c) {
return a + b + c;
double add(double a, double b) {
return a + b;
public static void main(String[] args) {
Calculator calc = new Calculator();
System.out.println(calc.add(5, 3));
System.out.println(calc.add(5, 3, 2));
System.out.println(calc.add(5.5, 3.3));
OUTPUT:
Program 17. Write a program to implement the concept of method overriding.
class Animal {
void sound() {
System.out.println("Animal makes a sound");
class Dog extends Animal {
@Override
void sound() {
System.out.println("Dog barks");
class Cat extends Animal {
@Override
void sound() {
System.out.println("Cat meows");
public class Main {
public static void main(String[] args) {
Animal animal = new Animal();
Dog dog = new Dog();
Cat cat = new Cat();
animal.sound();
dog.sound();
cat.sound();
}
}
OUTPUT:
Program 18. Write a program to show abstraction using abstract class in java.
abstract class Animal {
abstract void sound();
abstract void eat();
class Dog extends Animal {
@Override
void sound() {
System.out.println("Dog barks");
@Override
void eat() {
System.out.println("Dog eats bones");
class Cat extends Animal {
@Override
void sound() {
System.out.println("Cat meows");
@Override
void eat() {
System.out.println("Cat eats fish");
public class Main1 {
public static void main(String[] args) {
Animal dog = new Dog();
Animal cat = new Cat();
dog.sound();
dog.eat();
cat.sound();
cat.eat();
OUTPUT:
Program 19. Write a program to show abstraction class using interfaces in java.
interface Animal {
void sound();
void eat();
class Dog implements Animal {
@Override
public void sound() {
System.out.println("Dog barks");
@Override
public void eat() {
System.out.println("Dog eats bones");
class Cat implements Animal {
@Override
public void sound() {
System.out.println("Cat meows");
@Override
public void eat() {
System.out.println("Cat eats fish");
public class Main2 {
public static void main(String[] args) {
Animal dog = new Dog();
Animal cat = new Cat();
dog.sound();
dog.eat();
cat.sound();
cat.eat();
OUTPUT:
Program 20. Write a program to implement multithreading in java.
class MyThread extends Thread {
@Override
public void run() {
for (int i = 0; i < 5; i++) {
try {
Thread.sleep(1000); // Pause for 1 second
} catch (InterruptedException e) {
System.out.println(e);
System.out.println(Thread.currentThread().getId() + " Value: " + i);
}
public class Main3 {
public static void main(String[] args) {
MyThread t1 = new MyThread();
MyThread t2 = new MyThread();
t1.start(); // Start thread t1
t2.start(); // Start thread t2
