ctype_alnum

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

ctype_alnumVerifica se os caracteres são alfanuméricos

Descrição

bool ctype_alnum ( string $text )

Verifica se todos os caracteres na string fornecida, text, é alfanumérico. No padrão C locale letras são [A-Za-z].

Parâmetros

text

A string a ser testada.

Valor Retornado

Retorna TRUE se todos caracteres em text são letra ou dígito, FALSE caso contrário.

Exemplos

Exemplo #1 Um exemplo da ctype_alnum() (usando o locale padrão)

<?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";
    }
}
?>

O exemplo acima irá imprimir:

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

Veja Também

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User Contributed Notes 5 notes

up
55
thinice at gmail dot com
7 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, '', $sUser))) {
    echo
'Your username is not properly formatted.';
}
?>
up
7
Anonymous
3 years ago
Quicktip: If ctype is not enabled by default on your server, replace ctype_alnum($var) with preg_match('/^[a-zA-Z0-9]+$/', $var).
up
2
Rory
6 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.
up
0
marcelocamargo at linuxmail dot org
8 months 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
-42
someone at example dot com
1 year ago
Both preg_match('/^[a-zA-Z0-9]+$/', $var) and ctype_alnum returns true if you type only numbers (e.g.: 123456).
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