Home »
PHP »
PHP Programs
PHP program to check whether given number is palindrome or not
Here, we are implementing a PHP program that will check whether a given integer number is palindrome or not.
By IncludeHelp Last updated : December 09, 2023
Problem statement
Given a number and we have to check whether it is palindrome or not using PHP program.
What is Palindrome number?
A number which is equal to its reverse number is said to be a palindrome number.
Example
The sample input and output for checking Palindrome number.
Input:
Number: 12321
Output:
It is palindrome number
Explanation:
Number is 12321 and its reverse number is 12321,
both are equal. Hence, it is a palindrome number.
Steps/Algorithm for Checking Palindrome Number
The following are the steps to check whether given number is in a Palindrome number or not:
- Assign the given number to a temporary variable, so that it can be used for comparing with the reverse number.
- Take a variable to store sum (i.e., reverse number)
- By using the while loop, extract the last digit of the number, use this number in the expression ($sum = $sum * 10 + $digit;) to make it reverse. And, then divide the number by 10. Repeat this step until the value is temporary number is zero.
- For checking the Palindrome number, compare the sum (reverse number) with the original (given) number.
PHP code to check palindrome number
<?php
//function: isPalindrome
//description
function isPalindrome($number)
{
//assign number to temp variable
$temp = $number;
//variable 'sum' to store reverse number
$sum = 0;
//loop that will extract digits from the last
//to make reverse number
while (floor($temp)) {
$digit = $temp % 10;
$sum = $sum * 10 + $digit;
$temp = $temp / 10;
}
//if number is equal to its reverse number
//then it will be a palindrome number
if ($sum == $number) {
return 1;
} else {
return 0;
}
}
//Main code to test above function
$num = 12321;
if (isPalindrome($num)) {
echo $num . " is a palindrome number";
} else {
echo $num . " is not a palindrome number";
}
?>
Output
12321 is a palindrome number
The following PHP topics are used in the above examples:
PHP Basic Programs »