ctype_xdigit

Check for character(s) representing a hexadecimal digit (PHP 4 >= 4.0.4, PHP 5)
bool ctype_xdigit ( string text )

Example 426. A ctype_xdigit() example

<?php

$strings = array('AB10BC99', 'AR1012', 'ab12bc99');

foreach ($strings as $testcase) {

    if (ctype_xdigit($testcase)) {

        echo "The string $testcase consists of all hexadecimal digits.\n";

    } else {

        echo "The string $testcase does not consist of all hexadecimal digits.\n";

    }

}
?>

The above example will output:

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The string AB10BC99 consists of all hexadecimal digits.

The string AR1012 does not consist of all hexadecimal digits.

The string ab12bc99 consists of all hexadecimal digits.

Code Examples / Notes » ctype_xdigit

This function shows its usefulness on a web site where a user is asked to entered a hexidecimal color code for a color. To prevent breaking W3C standard and having them enter in "neon-green" or the wrong type of code like 355511235. In conjunction with strlen() you could create a function like this: function check_valid_colorhex($colorCode) { // If user accidentally passed along the # sign, strip it off $colorCode = ltrim($colorCode, '#'); if ( ctype_xdigit($colorCode) && (strlen($colorCode) == 6 || strlen($colorCode) == 3)) return true; else return false; }

ctype_xdigit

Check for character(s) representing a hexadecimal digit (PHP 4 >= 4.0.4, PHP 5) bool ctype_xdigit ( string text )

Example 426. A ctype_xdigit() example

Code Examples / Notes » ctype_xdigit

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Check for character(s) representing a hexadecimal digit (PHP 4 >= 4.0.4, PHP 5)
bool ctype_xdigit ( string text )