How can special characters like \r impact the character count calculations in PHP when processing text area inputs?

Special characters like `\r` can impact character count calculations in PHP when processing text area inputs because they are counted as individual characters. To solve this issue, you can use the `mb_strlen` function in PHP with the `UTF-8` encoding parameter to accurately count the characters in the input text.

$input_text = $_POST['textarea_input'];
$character_count = mb_strlen($input_text, 'UTF-8');
echo "Character count: " . $character_count;