Convert snake to camel case and back with PHP

snake-to-camel.php

<?php

function camel_to_snake($input)
{
    return strtolower(preg_replace('/(?<!^)[A-Z]/', '_$0', $input));
}
function snakeToCamel($input)
{
    return lcfirst(str_replace(' ', '', ucwords(str_replace('_', ' ', $input))));
}


$camel = 'CreateUserProfile';
$snake = camel_to_snake($camel);
echo 'to_snake: ' . $snake . "\n";
$camel = snakeToCamel($snake);
echo 'toCamel: ' . $camel . "\n";