My answer is almost like this one: Pregmatch for at least 3 letters and for minus and apostrophe
So, I need too a regex for a name validation. But my rules are a little different:
can accept only one apostrophe (') or no one else -these are the only special characters that can be used ...(not mandatory and anywere in the name). it doesnt matters where you put the apostrophe
for ex:
d'amico => must be accepted;
d'amico' => no d''amico => no 'oneil => no dell'amore => yes damico => yes king kong => yes io => no io9 => no
8888 => no aaa+++? => no
Until now I have this code:
<?php
...
// Array errori
$error = array(); // o $error = []; se hai una versione di php recente
// Controllo il Nome Utente
if(trim($nome) == ''){
$error[] = 'Campo nome non compilato'; }
if (ctype_alnum($nome))
{$error[] = 'Se vuoi modificare il campo nome, assicurati che lo
stesso non contenga numeri al suo interno!'; }
if(strlen($nome) < 3 || strlen($nome) > 20){
$error[] = 'Il campo nome deve contenere minimo 3 caratteri e massimo 20 caratteri'; }
if (!preg_match("/^([A-Za-z|àèéìòù][A-Za-z'-]*?){3,}$/", $nome)) {
$error[] = 'Il campo nome contiene caratteri non ammessi'; }
...
?>
<html>...
<?php
if(!empty($error)){
echo '<center>';
echo implode('<br/>', $error);
echo '</center>';
}
?>
...
</html>
How can I combine everything into one string? Thank you in advance!
Using a negative lookahead you can assert that the string doesn't start with a ', whitespace, or contain 2 (or more) single quotes. Then you can just test that the string is between 3 and 20 characters long with your allowed character list.
(?!(.*?'.*?'|^[' ]))^[A-Za-z|àèéìòù ']{3,20}$
Regex Demo: https://regex101.com/r/QANVBo/1
PHP Demo: https://eval.in/659769
PHP Usage:
$array = array("d'amico", "dell'amore", "damico", "king kong", "io", "io9", "8888", "aaa+++?", "d'amico'", "d''amico", "'oneil");
foreach ($array as $term ) {
if(preg_match("/(?!(.*?'.*?'|^[' ]))^[A-Za-z|àèéìòù ']{3,20}$/", $term)) {
echo 'Matches:';
} else {
echo 'No Match:';
}
echo $term . "
";
}