ctype_alnum

(PHP 4 >= 4.0.4, PHP 5)

ctype_alnum -- Check for alphanumeric character(s)

Description

bool ctype_alnum ( string text)

Returns TRUE if every character in text is either a letter or a digit, FALSE otherwise. In the standard C locale letters are just [A-Za-z] and the function is equivalent to preg_match('/^[a-z0-9]*$/i', $text).

Example 1. A ctype_alnum() example (using the default locale)

<?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";
    }
}
?>

The above example will output:

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

See also ctype_alpha(), ctype_digit(), and setlocale().