Java Program to Check Palindrome Number

Posted in Java Tutorial

Updated on Oct 30, 2024

By Mari Selvan

👁️ 185 - Views

⏳ 4 mins

💬 1 Comment

Photo Credit to CodeToFun

🙋 Introduction

In the realm of programming, tasks involving numbers often include checking for special properties. One interesting property is whether a number is a palindrome.

A palindrome number reads the same backward as forward.

In this tutorial, we will explore a Java program designed to check whether a given number is a palindrome.

The program involves reversing the digits of the number and comparing it with the original number.

📄 Example

Let's delve into the Java code that accomplishes this task.

PalindromeChecker .java

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import java.util.Scanner;

public class PalindromeChecker {
  // Function to check if a number is a palindrome
  static boolean isPalindrome(int number) {
    int originalNumber = number;
    int reversedNumber = 0, remainder;

    // Reverse the digits of the number
    while (number != 0) {
      remainder = number % 10;
      reversedNumber = reversedNumber * 10 + remainder;
      number /= 10;
    }

    // If the reversed number is equal to the original number, it is a palindrome
    return originalNumber == reversedNumber;
  }

  // Driver program
  public static void main(String[] args) {
    // Replace this value with the number you want to check
    int number = 121;

    // Call the function to check if the number is a palindrome
    if (isPalindrome(number))
      System.out.println(number + " is a palindrome number.");
    else
      System.out.println(number + " is not a palindrome number.");
  }
}

💻 Testing the Program

To test the program with different numbers, modify the value of number in the main method.

Output

121 is a palindrome number.

Compile and run the program to check if the specified number is a palindrome.

🧠 How the Program Works

The program defines a class PalindromeChecker containing a static method isPalindrome that takes an integer number as input and returns true if the number is a palindrome, and false otherwise.
Inside the main method, replace the value of number with the desired number you want to check.
The program calls the isPalindrome method and prints the result using System.out.println.

📏 Between the Given Range

Let's delve into the java code that checks for palindrome numbers in the range 100 to 200.

isPalindrome.java

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public class PalindromeNumbersInRange {

  // Function to check if a number is a palindrome
  static boolean isPalindrome(int number) {
    int originalNumber = number;
    int reversedNumber = 0;

    // Reverse the number
    while (number != 0) {
      int digit = number % 10;
      reversedNumber = reversedNumber * 10 + digit;
      number /= 10;
    }

    // Check if the original number is equal to its reverse
    return originalNumber == reversedNumber;
  }

  // Driver program
  public static void main(String[] args) {
    System.out.println("Palindrome Numbers in the range 100 to 200:");

    // Check for palindrome numbers in the range
    for (int i = 100; i <= 200; i++) {
      if (isPalindrome(i)) {
        System.out.print(i + " ");
      }
    }
  }
}

💻 Testing the Program

Output

Palindrome Numbers in the range 100 to 200:
101 111 121 131 141 151 161 171 181 191

Compile and run the program to see the palindrome numbers in the range of 100 to 200.

🧠 How the Program Works

The program defines a class PalindromeNumbersInRange containing a static method isPalindrome that checks whether a given number is a palindrome.
Inside the method, it reverses the number and checks if the original number is equal to its reverse.
The main method iterates through numbers from 100 to 200 and prints the palindrome numbers.