Java program to compare two strings

import java.util.Scanner;

class CompareStrings

   public static void main(String args[])

      String s1, s2;

      Scanner in = new Scanner(System.in);

      System.out.println("Enter the first string");

      s1 = in.nextLine();

      System.out.println("Enter the second string");

      s2 = in.nextLine();

      if ( s1.compareTo(s2) > 0 )

         System.out.println("First string is greater than second.");

      else if ( s1.compareTo(s2) < 0 )

         System.out.println("First string is smaller than second.");

      else

         System.out.println("Both strings are equal.");

Interface in Java

interface Info

  static final String language = "Java";

  public void display();

class Simple implements Info

 public static void main(String []args)

    Simple obj = new Simple();

    obj.display();

  public void display()

    System.out.println(language + " is awesome");

import java.util.*;

class Palindrome

 public static void main(String args[])

      String original, reverse = "";

      Scanner in = new Scanner(System.in);

      System.out.println("Enter a string to check if it is a palindrome");

      original = in.nextLine();

      int length = original.length();

      for ( int i = length - 1; i >= 0; i-- )

         reverse = reverse + original.charAt(i);

      if (original.equals(reverse))

         System.out.println("Entered string is a palindrome.");

      else

         System.out.println("Entered string is not a palindrome.");

import java.util.*;

class ReverseString

 public static void main(String args[])

      String original, reverse = "";

      Scanner in = new Scanner(System.in);

      System.out.println("Enter a string to reverse");

      original = in.nextLine();

      int length = original.length();

      for ( int i = length - 1 ; i >= 0 ; i-- )

         reverse = reverse + original.charAt(i);

      System.out.println("Reverse of entered string is: "+reverse);

import java.util.Scanner;

class FloydTriangle

public static void main(String args[])

      int n, num = 1, c, d;

      Scanner in = new Scanner(System.in);

      System.out.println("Enter the number of rows of floyd's triangle you want");

      n = in.nextInt();

      System.out.println("Floyd's triangle :-");

      for ( c = 1 ; c <= n ; c++ )

         for ( d = 1 ; d <= c ; d++ )

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

            num++;

         System.out.println();

import java.util.*;

class ArmstrongNumber

 public static void main(String args[])

      int n, sum = 0, temp, r;

      Scanner in = new Scanner(System.in);

      System.out.println("Enter a number to check if it is an armstrong number");

      n = in.nextInt();

      temp = n;

      while( temp != 0 )

         r = temp%10;

         sum = sum + r*r*r;

         temp = temp/10;

       if ( n == sum )

         System.out.println("Entered number is an armstrong number.");

      else

         System.out.println("Entered number is not an armstrong number.");

import java.util.*;

class PrimeNumbers

 public static void main(String args[])

      int n, status = 1, num = 3;

      Scanner in = new Scanner(System.in);

      System.out.println("Enter the number of prime numbers you want");

      n = in.nextInt();

      if (n >= 1)

         System.out.println("First "+n+" prime numbers are :-");

         System.out.println(2);

      for ( int count = 2 ; count <=n ;  )

         for ( int j = 2 ; j <= Math.sqrt(num) ; j++ )

            if ( num%j == 0 )

               status = 0;

               break;

         if ( status != 0 )

            System.out.println(num);

            count++;

         status = 1;

         num++;