 <p>This function takes a string argument as input</p> <p>The first thing it does is checks the recursive base case. We'll get back to that</p> <p>If the base case is not satisfied, it then checks to see if the first character matches the last character using this code:</p> <pre><code>if (substr($string,0,1) == substr($string,(strlen($string) - 1),1)) </code></pre> <p>If that does match, then the function recursively calls itself again but this time with the first and last character removed, this is done with this line</p> <pre><code>return Palindrome(substr($string,1,strlen($string) -2)); </code></pre> <p>If ever the first character does not match the last character, the function automatically outputs to html "STRING IS NOT A PALINDROME via <code>echo</code></p> <p>Now back to the base case I mentioned before, if the function successfully matches and removes the first and last character until there are one or no characters left, then the string has been confirmed to be a palindrome and it echos that string.</p> <p>If you need help with recursion let me know, I'll post a tutorial link</p>