Palindrome Class written in PHP 7.1.9. - isPalindrome

Palindrome.php

<?php
class Palindrome
{
    public static function isPalindrome($word)
    {
        $word = strtolower($word);
        
        $wordArray = str_split($word);
        for ($i = 0; $i <= count($wordArray); $i++) {
            $wordBackward = $wordBackward.$wordArray[count($wordArray)-$i];
        }
        
        //echo "Forward  : ".$word."\n";
        //echo "Backward : ".$wordBackward."\n";
        
        if ($word == $wordBackward)
            return true;
        else
            return false;
    }
}

echo Palindrome::isPalindrome('Deleveled');