What is the difference between using preg_replace and rtrim to remove numbers from the end of a string in PHP?

When removing numbers from the end of a string in PHP, using `preg_replace` allows for more flexibility as it can handle various patterns of numbers to be removed. On the other hand, `rtrim` is more straightforward and efficient when dealing with a specific character or set of characters at the end of a string.

// Using preg_replace to remove numbers from the end of a string
$string = "Hello123";
$cleaned_string = preg_replace('/\d+$/', '', $string);
echo $cleaned_string; // Output: Hello

// Using rtrim to remove numbers from the end of a string
$string = "Hello123";
$cleaned_string = rtrim($string, '0123456789');
echo $cleaned_string; // Output: Hello