Replace diacritic characters with “equivalent” ASCII in PHP?

Question

Related questions:

1. How to replace characters in a java String?
2. How to replace special characters with their equivalent (such as " á " for &

Answer 1

Try this:

function normal_chars($string)
{
    $string = htmlentities($string, ENT_QUOTES, 'UTF-8');
    $string = preg_replace('~&([a-z]{1,2})(acute|cedil|circ|grave|lig|orn|ring|slash|th|tilde|uml);~i', '$1', $string);
    $string = preg_replace(array('~[^0-9a-z]~i', '~-+~'), ' ', $string);
    return trim($string);
}

Examples:

echo normal_chars('Álix----_Ãxel!?!?'); // Alix Axel
echo normal_chars('áéíóúÁÉÍÓÚ'); // aeiouAEIOU
echo normal_chars('üÿÄËÏÖÜŸåÅ'); // uyAEIOUYaA

Based on the selected answer in this thread: URL Friendly Username in PHP?