The ctype_xdigit() function in PHP used to check each and every character of string/text are hexadecimal digit or not. It return TRUE if all characters are hexadecimal otherwise return FALSE . Syntax :

ctype_xdigit(string text)

Parameters Used:

• text : It is mandatory parameter which specifies the tested string.

Return Values: It returns TRUE if all characters of the string are hexadecimal otherwise return FALSE. Examples:

Input  :  ABCDEF0123
Output :  Yes

Input  : GFG2018
Output : No
   

Note :  It checking decimal digit or a character from [A-F, a-f].

Below programs illustrate the ctype_xdigit() function. Program: 1

 

<?php

// PHP program to check given string is 

// Hexadecimal character or not

​

$string = 'ABab012';

​

// Checking above string by using

// of ctype_xdigit() function.

if ( ctype_xdigit($string)) {

    // if true then return Yes

    echo "Yes \n";

​

} else {

​

    // if False then return No

    echo "No \n";

}

?>

Program: 2 Take one more example ctype_xdigit() function to check how it work when input contains uppercase lowercase and symbol character by using input as array of string.

 

<?php

// PHP program to check given string is 

//Hexadecimal character or not

​

$strings = array(

    'ABCDEF',

    'abcdef',

    '0123456789X',

    '0123456789',

    'Gg@(*&)',

    'GFG'

);

​

// Checking above given strings 

//by used of ctype_xdigit() function .

foreach ($strings as $test) {

    if (ctype_xdigit($test)) {

         echo "Yes \n";

    } else {

         echo "No \n";

    }

}

​

?>

References : http://php.net/manual/en/function.ctype-xdigit.php