{"id":797,"date":"2021-03-28T07:42:50","date_gmt":"2021-03-28T07:42:50","guid":{"rendered":"https:\/\/phptutorial.net\/?page_id=797"},"modified":"2025-04-05T14:31:01","modified_gmt":"2025-04-05T14:31:01","slug":"php-null","status":"publish","type":"page","link":"https:\/\/www.phptutorial.net\/php-tutorial\/php-null\/","title":{"rendered":"PHP null"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you will learn about the PHP NULL<\/code> type and how to check if a variable is null or not.<\/p>\n\n\n\n

Introduction to the PHP null type #<\/a><\/h2>\n\n\n\n

The null<\/code> is a special type in PHP. The null<\/code> type has only one value which is also null<\/code>.  The null<\/code> indicates the absence of a value for a variable<\/a>.<\/p>\n\n\n\n

A variable is null when you assign null<\/code> to it like this:<\/p>\n\n\n

<?php<\/span>\n\n$email = null<\/span>;\nvar_dump($email); \/\/ NULL<\/span><\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
In addition, when you use the unset()<\/code> function to unset a variable, the variable is also null. For example:<\/p>\n\n\n
<?php<\/span>\n\n$email = 'webmaster@phptutorial.net'<\/span>;\nunset<\/span>($email);\n\nvar_dump($email); \/\/ NULL<\/span><\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
PHP NULL and case-sensitivity #<\/a><\/h2>\n\n\n\n
PHP keywords are case-insensitive. Therefore, NULL is also case-insensitive. It means that you can use null<\/code>, Null<\/code>, or NULL<\/code> to represent the null<\/code> value. For example:<\/p>\n\n\n
<?php<\/span>\n\n$email = null<\/span>;\n$first_name = Null<\/span>;\n$last_name = NULL<\/span>;<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
It’s a good practice to keep your code consistent. If you use null<\/code> in the lowercase in one place, you should also use it in your whole codebase.<\/p>\n\n\n\n
Testing for NULL #<\/a><\/h2>\n\n\n\n
To check if a variable is null<\/code> or not, you use the is_null()<\/code> function. The is_null()<\/code> function returns true<\/code> if a variable is null<\/code>; otherwise, it returns false<\/code>. For example:<\/p>\n\n\n
<?php<\/span>\n\n$email = null<\/span>;\nvar_dump(is_null($email)); \/\/ bool(true)<\/span>\n\n$home = 'phptutorial.net'<\/span>;\nvar_dump(is_null($home)); \/\/ bool(false)<\/span><\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
To test if a variable is null<\/code> or not, you can also use the identical operator ===<\/code>. For example:<\/p>\n\n\n
<?php<\/span>\n\n$email = null<\/span>;\n$result = ($email === null<\/span>);\nvar_dump($result); \/\/ bool(true)<\/span>\n\n$home= 'phptutorial.net'<\/span>;\n$result = ($home === null<\/span>);\nvar_dump($result); \/\/ bool(false)<\/span><\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Summary #<\/a><\/h2>\n\n\n\n
    \n
  • PHP null type has a value called null, representing a variable with no value.<\/li>\n\n\n\n
  • Use the is_null()<\/code> function or ===<\/code> operator to compare a variable with null.<\/li>\n<\/ul>\n
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