We have given a variable and the task is to check whether the value of 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 value of variable $var is NULL, otherwise, returns FALSE.
Syntax
boolean is_null( $var )
Example:
PHP
<?php // PHP Program to check whether // a variable is null or not?$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:
True False False
