How to check Whether a Variable is Null in PHP? Last Updated : 21 Apr, 2025 Comments Improve Suggest changes Like Article Like Report We are given a variable and the task is to check whether the value of the given variable is null or not and returns a Boolean value using PHP. To check a variable is null or not, we use is_null() function. A variable is considered to be NULL if it does not store any value. It returns TRUE if the value of variable $var is NULL, otherwise, returns FALSE.Syntax:boolean is_null( $var )Example: This example checks whether a variable is null in PHP or not. PHP <?php // PHP Program to check whether // a variable is null or not? $var1 = NULL; $var2 = "\0"; // "\0" means null character $var3 = "NULL"; // $var1 has NULL value, so always give TRUE is_null($var1) ? print_r("True\n") : print_r("False\n"); // $var2 has '\0' value which consider as null in // c and c++ but here taken as string, gives FALSE is_null($var2) ? print_r("True\n") : print_r("False\n"); // $var3 has NULL string value so it will false is_null($var3) ? print_r("True\n") : print_r("False\n"); ?> Output:TrueFalseFalse Comment More info M manaschhabra2 Follow Improve Article Tags : Web Technologies PHP PHP Programs PHP-Misc 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