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    ctype_alnum

    (PHP 4 >= 4.0.4, PHP 5, PHP 7, PHP 8)

    ctype_alnum — Controlla i caratteri alfanumerici

    Descrizione

    ctype_alnum(mixed $text): bool

    Controlla che tutti i caratteri della string text fornita, siano alfanumerici.

    Elenco dei parametri

    text

    La stringa da testare.

    Nota:

    Se è fornito un integer tra -128 e 255, viene interpretato come il valore ASCII di un singolo carattere (ai valori negativi viene aggiunto 256 in modo da permettere i caratteri Extended ASCII). Qualsiasi altro intero è interpretato come una stringa contenente le cifre decimali dell'intero.

    Avviso

    As of PHP 8.1.0, passing a non-string argument is deprecated. In the future, the argument will be interpreted as a string instead of an ASCII codepoint. Depending on the intended behavior, the argument should either be cast to string or an explicit call to chr() should be made.

    Valori restituiti

    Restituisce true se ogni carattere in text è o una lettera o una cifra, false in caso contrario. When called with an empty string the result will always be false.

    Esempi

    Example #1 Un esempio di ctype_alnum() (usando il locale di default)

    <?php
    $strings     = array('AbCd1zyZ9', 'foo!#$bar');
    foreach (    $strings as $testcase) {
    if (    ctype_alnum($testcase)) {
    echo     "The string $testcase consists of all letters or digits.\n";
    } else {
    echo     "The string $testcase does not consist of all letters or digits.\n";
    }
    }
    ?>

    Il precedente esempio visualizzerà:

    The string AbCd1zyZ9 consists of all letters or digits.
The string foo!#$bar does not consist of all letters or digits.

    Vedere anche:

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    User Contributed Notes 4 notes

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    83
    thinice at gmail dot com
    15 years ago
    ctype_alnum() is a godsend for quick and easy username/data filtering when used in conjunction with str_replace().

    Let's say your usernames have dash(-) and underscore(_) allowable and alphanumeric digits as well.

    Instead of a regex you can trade a bit of performance for simplicity:

    <?php
    $sUser     = 'my_username01';
    $aValid = array('-', '_');

    if(!    ctype_alnum(str_replace($aValid, '', $sUser))) {
        echo     'Your username is not properly formatted.';
    }
    ?>
    up
    16
    Anonymous
    11 years ago
    Quicktip: If ctype is not enabled by default on your server, replace ctype_alnum($var) with preg_match('/^[a-zA-Z0-9]+$/', $var).
    up
    3
    marcelocamargo at linuxmail dot org
    8 years ago
    It is also important to note that the behavior of `ctype_alnum` differs according to the operating system. For UNIX-based operating system, if you pass a value that is not a string (or an overloaded object), independently of the value, it will always result in false. However, if we do the same on Windows, using, for example, -1 as literal (a minus and a number greater than 0), we'll have true as result.

    <?php var_dump(ctype_alnum(-1));
    // UNIX: bool(false)
    // Windows: bool(true)
    up
    -7
    Rory
    14 years ago
    Just for the record, Gentoo doesn't include this function by default. You'll have to recompile PHP with the "ctype" USE flag.
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