{"id":434,"date":"2021-03-15T08:23:10","date_gmt":"2021-03-15T08:23:10","guid":{"rendered":"https:\/\/phptutorial.net\/?page_id=434"},"modified":"2025-04-07T13:38:23","modified_gmt":"2025-04-07T13:38:23","slug":"php-not-operator","status":"publish","type":"page","link":"https:\/\/www.phptutorial.net\/php-tutorial\/php-not-operator\/","title":{"rendered":"PHP NOT operator"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you will learn how to use the PHP NOT operator (!) to build complex logical expressions.<\/p>\n\n\n\n

Introduction to the PHP NOT operator #<\/a><\/h2>\n\n\n\n

Unlike the logical AND<\/a> and OR<\/a> operators that accept two operands, the logical NOT operator accepts only one operand and negates the operand. <\/p>\n\n\n\n

In other words, the logical NOT operator returns true<\/code> if the operand is false<\/code> and returns false<\/code> if the operand is true<\/code>.<\/p>\n\n\n\n

PHP uses the both not<\/code> keyword and (!<\/code>) to represent the logical NOT operator.<\/p>\n\n\n

not expression<\/code><\/span><\/pre>\n\n\n
Or <\/p>\n\n\n
! expression<\/code><\/span><\/pre>\n\n\n
The following table illustrates the result of the logical NOT operator:<\/p>\n\n\n\n
Expression<\/th>not Expression<\/th><\/tr><\/thead>
true<\/code><\/td>false<\/code><\/td><\/tr>
false<\/code><\/td>true<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
The logical NOT operator is also known as the logical negation operator.<\/p>\n\n\n\n
PHP NOT operator examples #<\/a><\/h2>\n\n\n\n
The following example illustrates how to use the logical not operator (!<\/code>):<\/p>\n\n\n
<?php<\/span>\n\n$priority = 5<\/span>;\nvar_dump( ! $priority < 5<\/span> );<\/span><\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
bool(true<\/span>)<\/code><\/span>Code language:<\/span> JavaScript<\/span> (<\/span>javascript<\/span>)<\/span><\/small><\/pre>\n\n\n
In this example, PHP evaluate the expression ! $priority < 5<\/code> in the following order:<\/p>\n\n\n\n
Try it<\/a><\/p>\n\n\n\n