Tuesday, 4 June 2013

Simple palindrome program in PHP

» What is Palindrome?

It is a word or phrase that is the same spelled forwards and backwards. Example: rotator, peeweep, reifier, racecar, etc.

» Find string palindrome or not in PHP using strrev() function

<?php
$word = "racecar";  // declare a varibale
echo "String: " . $word . "<br>";
$reverse = strrev($word); // reverse the word
if ($word == $reverse) // compare if  the original word is same as the reverse of the same word
    echo 'Output: This string is a palindrome';
else
    echo 'Output: This is not a palindrome';
?>

» Find string palindrome or not in PHP without using strrev() function

<?php
$mystring = "racecar"; // set the string
echo "String: " . $mystring;
$myArray = array(); // php array
$myArray = str_split($mystring); //split the array
$len = sizeof($myArray); // get the size of array
$newString = "";

for ($i = $len; $i >= 0; $i--) {
    $newString.=$myArray[$i];
}
echo "<br>";
if ($mystring == $newString) {
    echo "Output: " . $mystring . " is a palindrome";
} else {
    echo "Output: " . $mystring . " is not a palindrome";
}
?>