PHP | is_null() Function (original) (raw)

Last Updated : 11 Jul, 2025

The is_null() function is an inbuilt function in PHP which is used to find whether a variable is NULL or not.

Syntax:

boolean is_null ( $var )

Parameters: This function accepts a single parameter as shown in above syntax and described below.

• $var: Variable to check if it is NULL or not.

Return value: It returns a boolean value. That is, it returns TRUE when $var will be NULL, otherwise it returns FALSE.

Below programs illustrate the is_null() function in PHP:

Program 1:

PHP `

`

Output:

True False False False

Program 2:

PHP `

`

Output:

True True True True True True True True False False

Reference: https://www.php.net/manual/en/function.is-null.php