- preg_replace_callback: documentation ( source)
- strrev: documentation ( source)
<?php
$strings = [
"i like to eat apple",
"orange",
"Surprise!"
];
foreach ($strings as $string) {
echo preg_replace_callback(
'~[a-z]+(?=[^a-z]*$)~i',
fn($m) => strrev($m[0]),
$string
);
echo "\n---\n";
}