PHP | IntlChar::isalnum () Function Last Updated : 11 Jul, 2025 Comments Improve Suggest changes Like Article Like Report The IntlChar::isalnum() function is an inbuilt function in PHP which is used to check the given input is an alphanumeric character (Digit or Letter) or not. It returns TRUE for characters with general categories "L" (letters) and "Nd" (decimal digit numbers). Syntax: bool IntlChar::isalnum( $codepoint ) Parameters: This function accepts single parameter $codepoint which is mandatory. The input parameter is an integer values or character, which is encoded as a UTF-8 string. Return Value: If $codepoint is alphanumeric character then it returns True, otherwise returns False. Program 1: PHP <?php // PHP code to illustrate IntlChar::isalnum() // Function // Input data is character type var_dump(IntlChar::isalnum("D")); // Input data is string type var_dump(IntlChar::isalnum("Geeksforgeeks")); // Input data is integer type var_dump(IntlChar::isalnum("234")); // Input data is special character type var_dump(IntlChar::isalnum("*")); ?> Output: bool(true) NULL NULL bool(false) Program 2: PHP <?php // PHP code to illustrate IntlChar::isalnum() // function // Declare an array $arr $arr = array("4", "20001111", "^", " ", "*", "GeeksforGeeks"); // Loop run for every array element foreach ($arr as $val){ // Check each element as code point data var_dump(IntlChar::isalnum($val)); } ?> Output: bool(true) NULL bool(false) NULL bool(false) NULL Related Articles: PHP | IntlChar::isalpha() FunctionPHP | IntlChar::isdigit() FunctionPHP | IntlChar::isblank() FunctionPHP | IntlChar::isbase() Function Reference: https://www.php.net/manual/en/intlchar.isalnum.php Comment J jit_t Follow 0 Improve J jit_t Follow 0 Improve Article Tags : Web Technologies PHP PHP-function Explore PHP Tutorial 8 min read BasicsPHP Syntax 4 min read PHP Variables 5 min read PHP | Functions 8 min read PHP Loops 4 min read ArrayPHP Arrays 5 min read PHP Associative Arrays 4 min read Multidimensional arrays in PHP 5 min read Sorting Arrays in PHP 4 min read OOPs & InterfacesPHP Classes 2 min read PHP | Constructors and Destructors 5 min read PHP Access Modifiers 4 min read Multiple Inheritance in PHP 4 min read MySQL DatabasePHP | MySQL Database Introduction 4 min read PHP Database connection 2 min read PHP | MySQL ( Creating Database ) 3 min read PHP | MySQL ( Creating Table ) 3 min read PHP AdvancePHP Superglobals 6 min read PHP | Regular Expressions 12 min read PHP Form Handling 4 min read PHP File Handling 4 min read PHP | Uploading File 3 min read PHP Cookies 9 min read PHP | Sessions 7 min read Like