In what scenarios would it be recommended to use built-in PHP functions like `mb_count_chars()` or `count_chars_unicode()` for character counting tasks?

When dealing with multibyte strings or Unicode characters in PHP, it is recommended to use built-in functions like `mb_count_chars()` or `count_chars_unicode()` for accurate character counting. These functions handle the complexities of multibyte encoding and Unicode characters, ensuring that each character is properly counted regardless of its encoding.

// Example of using mb_count_chars() to count characters in a multibyte string
$string = "こんにちは"; // Japanese greeting
$charCount = mb_count_chars($string, 1); // Count each unique character
echo count($charCount); // Output: 5