Easy
What is your name?
Write a programme that asks the user for their name and prints it.
Show answer:
"import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter your name: ");
String name = sc.nextLine();
System.out.println("Your name is: " + name);
sc.close();
}
}Add two numbers
Write a programme that asks the user to input two numbers and prints their sum.
Show answer:
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter the first number: ");
int num1 = sc.nextInt();
System.out.print("Enter the second number: ");
int num2 = sc.nextInt();
int sum = num1 + num2;
System.out.println("The sum is: " + sum);
sc.close();
}
}Multiply two numbers
Write a programme that asks the user to input two numbers and prints their sum.
Show answer:
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter the first number: ");
double num1 = sc.nextDouble();
System.out.print("Enter the second number: ");
double num2 = sc.nextDouble();
double product = num1 * num2;
System.out.println("The product is: " + product);
sc.close();
}
}Medium
Read and display a sentence
Ask the user for a sentence and print it.
Show answer:
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter a sentence: ");
String sentence = sc.nextLine();
System.out.println("Your sentence: " + sentence);
sc.close();
}
}Check prime number
Ask the user to input a number and check if it is prime.
Show answer:
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter a number: ");
int num = sc.nextInt();
boolean isPrime = true;
for (int i = 2; i <= num / 2; i++) {
if (num % i == 0) {
isPrime = false;
break;
}
}
if (isPrime && num > 1) {
System.out.println(num + " is a prime number.");
} else {
System.out.println(num + " is not a prime number.");
}
sc.close();
}
}Count vowels in a string
Ask the user for a string and count the number of vowels (a, e, i, o, u).
Show answer:
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter a string: ");
String input = sc.nextLine();
int vowelCount = 0;
for (int i = 0; i < input.length(); i++) {
char c = input.charAt(i);
String vowels = "aeiouAEIOU";
If(vowels.contains(Character.toString(c)))
vowelCount++;
}
System.out.println("Number of vowels: " + vowelCount);
sc.close();
}
}Hard
Factorial of a number
Write a programme to calculate the factorial of a number using a loop.
Show answer:
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter a number: ");
int num = sc.nextInt();
long factorial = 1;
for (int i = 1; i <= num; i++) {
factorial *= i;
}
System.out.println("Factorial of " + num + " is: " + factorial);
sc.close();
}
}Sum of digits
Write a programme that calculates the sum of digits of a number entered by the user.
Show answer:
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.print("Enter a number: ");
int num = sc.nextInt();
int sum = 0;
while (num != 0) {
sum += num % 10;
num /= 10;
}
System.out.println("Sum of digits: " + sum);
sc.close();
}
}Palindrome checker
Write a programme that checks if the input string is a palindrome (a word or phrase that reads the same forwards and backwards, ignoring spaces, punctuation, and case).
Show answer:
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
// Create a scanner object to read input from the user
Scanner sc = new Scanner(System.in);
// Ask the user for a string input
System.out.print("Enter a string: ");
String input = sc.nextLine();
// Remove spaces and convert to lowercase to ensure comparison is case insensitive
String cleanedInput = input.replaceAll("[^a-zA-Z0-9]", "").toLowerCase();
// Initialise a boolean flag to check if it's a palindrome
boolean isPalindrome = true;
// Loop to check if the string is the same forwards and backwards
for (int i = 0; i < cleanedInput.length() / 2; i++) {
if (cleanedInput.charAt(i) != cleanedInput.charAt(cleanedInput.length() - 1 - i)) {
isPalindrome = false; // Set flag to false if not a palindrome
break; // Exit the loop if we find a mismatch
}
}
// Display the result
if (isPalindrome) {
System.out.println(input + " is a palindrome.");
} else {
System.out.println(input + " is not a palindrome.");
}
// Close the scanner
sc.close();
}
}
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