Compares two strings and ignores (but does not replace) accents. PHP

Question

I get (for example) two strings:

$a = "joao";
$b = "joão";

if (strtoupper($a) == strtoupper($b)) {
    echo $b;
}

I hope it is true even with the accent. However, I need it to ignore accents rather than replace, since I need to output "joão" instead of "joao".

All the answers I've seen replace "ã" with "a" instead of making the comparison true. I've been reading about normalization but I can't get it to work either. Any ideas? Thanks.

Answer 1

I'd like to share an elegant solution that avoids using htmlentities and doesn't require manually listing all character replacements. This is the php translation of this post.

function removeAccents($str) {
    return preg_replace('/[\x{0300}-\x{036f}]/u',"",normalizer_normalize($str,Normalizer::FORM_D));
}

$a = "joaoaaeeA";
$b = "joãoâàéèÀ";

var_dump(removeAccents($a) === removeAccents($b));

Output:

bool(true)

Answer 2

Just convert the accented characters to their unaccented counterparts and then compare the strings. The function in my answer will remove accents for you.

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

$a = "joaoaaeeA";
$b = "joãoâàéèÀ";

var_dump(removeAccents($a) === removeAccents($b));

Output:

bool(true)

Demo