Java Program to check if entered number is palindrome or not

Below program checks whether entered number is palindrome or not.


Palindrome number is the number which is same when you write it straight or reverse. For example, 121 is same even if you write it reverse. Such numbers are called as palindrome numbers.

import java.util.Scanner;

public class PalindromCheck {

         public static void main(String[] args) {

         int reminder;

         int n;

         int d=0;

         Scanner sc=new Scanner(System.in);

         System.out.println("Enter number to check");

         n=sc.nextInt();

         int tempnum=n;

         while(n>0)

        {

             reminder=n%10;

            d=(d*10)+reminder;

             n=n/10;

       }

        if(tempnum==d)

       {

               System.out.printf("Number %d is palindrome",d);

       }

       else

      {

              System.out.printf("Number %d is not palindrome",d);

       }

   }

}

Output

Enter number to check

121

Number 121 is palindrome



Enter number to check

233

Number 332 is not palindrome

Explaination

• import java.util.Scanner-This statement tells the compiler to import Scanner class to program which is contained in utils package. The Scanner class has a methods defined to accept input entered by user.

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• public class PalindromCheck - is the name of the class.

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• public static void main(String[] args)- is the main() method which is the starting point of any Java Program.

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• Next we declared the three integer variables reminder, n and d with d initialized to '0' . Next we created object of Scanner Class to accept value entered by user,and Prompted user to Enter the value.

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• The value entered by user was stored in variable 'n' which is already declared. After that the value stored in 'n' is taken into another variable 'tempnum'.

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• To check whether the number palindrome or not, We used WHILE loop and till the number is greater than ZERO , we take out the modules of the number , then we multiply variable 'd' with 10 and with adding reminder value which is stored in variable 'reminder'.  And last we divide the number by 10 and store in same variable . This whole cycle is performed until the number entered is greater than ZERO.

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• And finally we compare if the original number which was stored in variable 'tempnum' and the new number which is stored in 'd' matches or not. If they matches , then the number is palindrome. Other wise , the number is not palindrome.