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 Create Quiz Comment J jit_t Follow 0 Improve J jit_t Follow 0 Improve Article Tags : Web Technologies PHP PHP-function Explore BasicsPHP Syntax4 min readPHP Variables5 min readPHP | Functions6 min readPHP Loops4 min readArrayPHP Arrays5 min readPHP Associative Arrays4 min readMultidimensional arrays in PHP5 min readSorting Arrays in PHP4 min readOOPs & InterfacesPHP Classes2 min readPHP | Constructors and Destructors5 min readPHP Access Modifiers4 min readMultiple Inheritance in PHP4 min readMySQL DatabasePHP | MySQL Database Introduction4 min readPHP Database connection2 min readPHP | MySQL ( Creating Database )3 min readPHP | MySQL ( Creating Table )3 min readPHP AdvancePHP Superglobals6 min readPHP | Regular Expressions12 min readPHP Form Handling4 min readPHP File Handling4 min readPHP | Uploading File3 min readPHP Cookies9 min readPHP | Sessions7 min read Like