What is the PHP function to sanitize a string?

The PHP function to sanitize a string is filter_var(). It can be used to apply filters and sanitization options specifically designed for strings, such as removing HTML tags, escaping special characters, and stripping or encoding unwanted characters. The filter_var() function provides a convenient and reliable way to sanitize strings in PHP. To learn more, visit: http://php.net/manual/en/function.filter-var.php