PHP Program to Check Palindrome Number

Posted in PHP Tutorial

Updated on Jan 11, 2024

By Mari Selvan

👁️ 223 - 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 PHP 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 PHP code that accomplishes this task.

isPalindrome

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<?php
// Function to check if a number is a palindrome
function isPalindrome($number)
{
  $originalNumber = $number;
  $reversedNumber = 0;

  // Reverse the digits of the number
  while ($number != 0)
  {
    $remainder = $number % 10;
    $reversedNumber = $reversedNumber * 10 + $remainder;
    $number = (int)($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
$number = 121;

// Call the function to check if the number is a palindrome
if (isPalindrome($number)) echo "$number is a palindrome number.\n";
else echo "$number is not a palindrome number.\n";

?>

💻 Testing the Program

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

Output

121 is a palindrome number.

🧠 How the Program Works

The program defines a function isPalindrome that takes an integer $number as input and returns true if the number is a palindrome, and false otherwise.
Inside the main program, replace the value of $number with the desired number you want to check.
The program calls the isPalindrome function and prints the result using echo.

📏 Between the Given Range

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

isPalindrome.php

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<?php
// Function to check if a number is palindrome
function isPalindrome($number)
{
  $originalNumber = $number;
  $reverse = 0;

  while ($number > 0)
  {
    $digit = $number % 10;
    $reverse = $reverse * 10 + $digit;
    $number = (int)($number / 10);
  }

  return $originalNumber == $reverse;
}

// Driver program
echo "Palindrome Numbers in the range 100 to 200:\n";

for ($i = 100;$i <= 200;$i++)
{
  if (isPalindrome($i))
  {
    echo "$i ";
  }
}

?>

💻 Testing the Program

Output

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

The program is designed to check and print 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 uses a while loop to reverse the digits of the number.
The main section iterates through the numbers from 100 to 200 and prints the palindrome numbers.