Are there any security considerations to keep in mind when passing variables between JavaScript and PHP scripts in a web application?

When passing variables between JavaScript and PHP scripts in a web application, it is important to sanitize and validate user input to prevent security vulnerabilities such as cross-site scripting (XSS) attacks. One way to ensure secure data transfer is to use PHP functions like htmlspecialchars() to escape special characters before sending data to the database.

// Sanitize user input before passing it to the database
$variable = htmlspecialchars($_POST['variable']);