Palindrome Number
April 4, 2022 • By Tomy • 0 Comments
/**
* Java program to check if number is Palindrome.
* A palindrome number is a number that remains the same when its digits are reversed.
*/
public class Palindrome {
public static void main(String args[]){
System.out.println(“Is 121 palindrome? ” + isPalindrome(121));
System.out.println(“Is 12321 palindrome? ” + isPalindrome(12321));
System.out.println(“Is 1212 palindrome? ” + isPalindrome(1212));
//another way to check if int number is palindrome or not in java
System.out.println(“Is 121 palindrome? ” + isPalindrome2(121));
System.out.println(“Is 12321 palindrome? ” + isPalindrome2(12321));
System.out.println(“Is 1212 palindrome? ” + isPalindrome2(1212));
}
/** Java Program to check if given number is Palindrom or not */
public static boolean isPalindrome
public class PalindromeNumber {
public static void main(String[] args) {
System.out.println(“Enter the number to check if it is a palindrome”);
Scanner sc = new Scanner(System.in);
int number = sc.nextInt();
boolean flag = false;
int temp = number, reverse = 0;
while (temp != 0) {
reverse = reverse * 10 + temp % 10;
temp /= 10;
}
if (number == reverse) {
flag = true;
}
if (flag == true) {
System.out.println(“The given number is a palindrome.”);
} else {
System.out.println(“The given number is not a palindrome.”);
}
} // main method ends here
} //class ends here
A palindrome number is a number that is equal to its reverse. For example, 121 is a palindrome because it is equal to its reverse 121. Similarly, the number 565 is also a palindrome because it is equal to its reverse 565.
In this program we first take a number from user and store it in an integer variable num. Then we use the while loop to iterate until num > 0. In each iteration of while loop, we extract the last digit of user entered number by using modulus operator % (num % 10). After that we multiply the reverse variable by 10 and add last digit to reverse like:
reverse = (reverse * 10) + lastDigit;
import java.util.Scanner;
public class Palindrome{
public static void main(String[] args){
int r,sum=0,temp;
Scanner sc = new Scanner(System.in);
System.out.println(“enter value :”);
int n=sc.nextInt();
temp=n;
while(n>0){
r=n%10;
sum=(sum*10)+r;
n=n/10;
}
if(temp==sum)
System.out.println(“palindrome number “);
else
System.out.println(“not palindrome”);
}
}
import java.io.*;
class PalindromeExample{
public static void main(String args[])throws IOException{
int r,sum=0,temp;
BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
System.out.println(“Enter your number”);
int n=Integer.parseInt(in.readLine()); //It is the number variable to be checked for palindrome
temp=n;
while(n>0){
r=n%10; //getting remainder
sum=(sum*10)+r;
n=n/10;
}
if(temp==sum)
System.out.println(“palindrome number “);
else
System.out.println(“not palindrome”);
}
}
Save the below program as Palindrome.java.
import java.util.*;
public class Palindrome {
public static void main(String[] args) {
int num = 121, reversedInteger = 0, remainder, originalInteger;
originalInteger = num;
// reversed integer is stored in variable
while( num != 0 )
{
remainder = num % 10;
reversedInteger = reversedInteger * 10 + remainder;
num /= 10;
}
if (originalInteger == reversedInteger) System.out.println(originalInteger + ” is a palindrome.”);
else System.out.println(originalInteger + ” is not a palindrome.”);
}
}
A palindrome is a word, phrase, number, or other sequence of characters which reads the same backward as forward. Examples of numerical palindromes are:
23322
110011
54322345
For a given number num, write a function to test if it’s a numerical palindrome or not and return a boolean (true if it is and false if not). Return “Not valid” if the input is not an integer or less than 0.
Tomy is a contributor at AskMeCode. We are committed to providing well-researched, accurate, and valuable content to our readers.
