How can the use of $_REQUEST in PHP scripts affect security and data integrity?

Using $_REQUEST in PHP scripts can pose security risks as it combines the values of $_GET, $_POST, and $_COOKIE. This can potentially lead to vulnerabilities such as injection attacks or data manipulation. To improve security and data integrity, it is recommended to use $_GET or $_POST specifically based on the expected input.

// Use $_GET or $_POST instead of $_REQUEST for improved security
$value = isset($_POST['input']) ? $_POST['input'] : '';