JavaScript Program to Check Palindrome Number

Posted in JavaScript Tutorial

Updated on Jan 11, 2024

By Mari Selvan

👁️ 421 - Views

⏳ 4 mins

💬 1 Comment

JavaScript Program to Check Palindrome Number

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 JavaScript 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 JavaScript code that accomplishes this task.

isPalindrome.js

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// Function to check if a number is a palindrome
function isPalindrome(number) {
  const originalNumber = number;
  let reversedNumber = 0,
    remainder;

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

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

// Driver program
// Replace this value with the number you want to check
const number = 121;

// Call the function to check if the number is a palindrome
if (isPalindrome(number)) {
  console.log(`${number} is a palindrome number.`);
} else {
  console.log(`${number} is not a palindrome number.`);
}

💻 Testing the Program

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

Output

121 is a palindrome number.

Run the script to check if the specified number is a palindrome.

🧠 How the Program Works

The program defines a function isPalindrome that takes a number as input and returns true if the number is a palindrome, and false otherwise.
Replace the value of number in the main program with the desired number you want to check.
The program calls the isPalindrome function and prints the result using console.log.

📏 Between the Given Range

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

isPalindrome.js

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// Function to check if a number is palindrome
function isPalindrome(number) {
  const originalNumber = number;
  let reversedNumber = 0,
    remainder;

  while (number !== 0) {
    remainder = number % 10;
    reversedNumber = reversedNumber * 10 + remainder;
    number = Math.floor(number / 10);
  }

  return originalNumber === reversedNumber;
}

// Check palindrome numbers in the range of 100 to 200
const startRange = 100;
const endRange = 200;

console.log("Palindrome Numbers in the range 100 to 200:");

for (let i = startRange; i <= endRange; i++) {
  if (isPalindrome(i)) {
    process.stdout.write(i + " ");
  }
}

console.log();

💻 Testing the Program

Output

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

Run the script to see the palindrome numbers in the range of 100 to 200.

🧠 How the Program Works

The program defines a function isPalindrome that checks if a given number is a palindrome.
Inside the function, it reverses the digits of the number and compares it with the original number.
The main section checks for palindrome numbers in the specified range (100 to 200) and prints the results.