Java Program For Checking A Number Palindrome

Just like palindrome string we discussed in our previous article and wrote a program for checking the palindrome string,same rule applies for the palindrome number.A number is palindrome if it remains same after reversing sequence of its digits.For example- suppose we have a number 121, if we reverse it then we will get a the same number 121, so the given number is a palindrome.Similarly 1221,525,52525 etc all are palindrome numbers.

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Now after knowing the definition of a palindrome number we can write our code easily.So here is the algorithm we will appy for writing the program-

• Get the user input,the number which we are going to check for palindrome, for this purpose we will use Scanner class in java


• Store that number in a int variable


• Reverse the scanned number and store it in an another int variable


• Compare the values of both int variables and print the result accordingly

Program-

package in.blogger.tutorialsinn

import java.util.Scanner;

public class NumberPalindrome {

 public static void main(String[] args) {

  Scanner sc = new Scanner(System.in);
  System.out.println("Enter the number you want to check");
  int number = sc.nextInt();
  int temp = number;

  // calculating length of number
  int length = (int) (Math.log10(temp) + 1);

  // calculating reverse number
  int rev = 0;
  for (int i = 1; i <= length; i++) {
   int rem = temp % 10;
   temp = temp / 10;

   rev = (rev * 10) + rem;
  }

  System.out.println("reverse number is " + rev);

  // checking for equality and printing result
  if (number == rev) {
   System.out.println("Given number is a palindrome");
  } else {
   System.out.println("Given number is not a palindrome");
  }
 }
}

Output-
Enter the number you want to check
121
reverse number is 121
Given number is a palindrome
I hope that you now understood the flow of whole program and can use your own logic for writing another palindrome program.

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