Ctype Functions
PHP Manual


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

ctype_xdigit Check for character(s) representing a hexadecimal digit


bool ctype_xdigit ( string $text )

Checks if all of the characters in the provided string, text, are hexadecimal 'digits'.



The tested string.

Return Values

Returns TRUE if every character in text is a hexadecimal 'digit', that is a decimal digit or a character from [A-Fa-f] , FALSE otherwise.


Example #1 A ctype_xdigit() example

= array('AB10BC99''AR1012''ab12bc99');
foreach (
$strings as $testcase) {
    if (
ctype_xdigit($testcase)) {
"The string $testcase consists of all hexadecimal digits.\n";
    } else {
"The string $testcase does not consist of all hexadecimal digits.\n";

The above example will output:

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.



If an integer between -128 and 255 inclusive is provided, it is interpreted as the ASCII value of a single character (negative values have 256 added in order to allow characters in the Extended ASCII range). Any other integer is interpreted as a string containing the decimal digits of the integer.

See Also

Ctype Functions
PHP Manual