How can the use of utf8_decode() function impact the display of special characters in PHP and what are the alternatives?

Using utf8_decode() function in PHP can impact the display of special characters by converting UTF-8 encoded characters to ISO-8859-1 encoding, which may result in incorrect or garbled display of special characters. An alternative approach is to ensure that your PHP files are properly encoded in UTF-8 and use appropriate functions like utf8_encode() or mb_convert_encoding() to handle character encoding conversions.

// Properly encoding PHP files in UTF-8
header('Content-Type: text/html; charset=UTF-8');

// Using mb_convert_encoding() to handle character encoding conversions
$utf8_string = "Special characters: é, ü, ñ";
$iso_string = mb_convert_encoding($utf8_string, 'ISO-8859-1', 'UTF-8');

echo $iso_string;