PHP | IntlChar::isalpha() Function Last Updated : 11 Jul, 2025 Comments Improve Suggest changes Like Article Like Report The IntlChar::isalpha() function is an inbuilt function in PHP which is used to check the given input is an alphanumeric character or not. Syntax: bool IntlChar::isalpha( $codepoint ) Parameters: The IntlChar::isalpha() function accept single parameter $codepoint which is mandatory. The input parameter is an integer value or character, which is encoded as a UTF-8 string.Return Value: If $codepoint is an alphanumeric character then it returns True, otherwise return False. Below programs illustrate the IntlChar::isalpha() function in PHP: Program 1: PHP <?php // PHP code to illustrate IntlChar::isalpha() // function // Input data is character type var_dump(IntlChar::isalpha("G")); // Input data is string type var_dump(IntlChar::isalpha("G\n")); // Input data is string type var_dump(IntlChar::isalpha("Geeksforgeeks")); // Input data is number var_dump(IntlChar::isalpha("2018")); // Input data is single digit var_dump(IntlChar::isalpha("5")); ?> Output: bool(true) NULL NULL NULL bool(false) Program 2: PHP <?php // PHP code to illustrate IntlChar::isalpha() // Declare an array $arr $arr = array("G", "GeeksforGeeks", "^", "1001", "6", "\u{2018}"); // Loop run for every array element foreach ($arr as $val){ // Check each element as code point data var_dump(IntlChar::isalpha($val)); } ?> Output: bool(true) NULL bool(false) NULL bool(false) bool(false) Related Articles: PHP | IntlChar::isdigit() FunctionPHP | IntlChar::isblank() FunctionPHP | IntlChar::isbase() Function Reference: https://www.php.net/manual/en/intlchar.isalpha.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