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Palindrome in php

What is Palindrome?

A palindrome is a word, phrase, number, or sequence of characters which reads the same in either direction. The words A and I are the simplest and smallest palindromes. Few of the most commonly used are :-
RACECAR LEVEL CIVIC POP MADAM EYE NUN RADAR

The word palindrome is derived from the Greek palíndromos, meaning running back again (palín = AGAIN + drom–, drameîn = RUN).

Words like LIVE and STRAW (which read EVIL and WARTS backwards) are not themselves palindromes but the phrases LIVE EVIL and STRAW WARTS are. A palindrome is not necessarily a single word.

While creating palindrome, it is usually accepted that punctuation and word spacings are ignored, and so the famous MADAM, I’M ADAM is a valid palindrome.

Here are a few good ones:

    Do geese see God?
    Murder for a jar of red rum.
    Some men interpret nine memos.
    Never odd or even.

palindrome
A famous palindrome “Able was I ere I saw Elba” purportedly spoken by Napoleon, referring to his first sighting of Elba, the island where the British exiled him.

How to verify a word is palindrome ?

Find given string is palindrome or not in PHP using native strrev() function

<?php
$word = 'madam';  // declare a varibale
echo 'String: <b>' . $word . '</b>';
$reverse = strrev($word); // reverse the word
if ($word == $reverse) // compare if the original word is same as the reverse of it
    echo ' is a palindrome';
else
    echo ' is not a palindrome';
?>

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

<?php
$mystring = 'madam'; // set the string
echo 'String: <b>' . $mystring . '</b>';

$myArray = array(); // initialize an array
$myArray = str_split($mystring); //split into array
$len = sizeof($myArray); // get the size of array
$newString = '';

for ( $i = $len; $i >= 0; $i-- ) {
    $newString .= $myArray[$i];
}

if ( $mystring == $newString ) {
    echo ' is a palindrome';
} else {
    echo ' is not a palindrome';
}
?>
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By Swatantra Kumar

Swatantra is an Open Source evangelist, a technologist and researcher. Professionally, he does software development, software architecture, server administration and project management. When he's not writing software, he enjoys building web entities and servers, reading about and working with new technologies, and trying to get his friends to make the move to open source software. He's written, co-written and published many articles in international journals, on various domains/topics including Open Source, Networks, Computer Organization, Mobile Technologies, and Business Intelligence. He made a proposal for an information management system at University level during graduation days.

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