What are the PHP functions used to sanitize input and output?

Question

this question appeared in Bca semester exam,i don't know the proper answer..can u help me?!

Answer 1

Hmm depends on what for? There is htmlspecialchars and strip_tags for dealing with HTML, addslashes for dealing with quotes, mysqli_real_escape_string and pg_escape_literal and pg_escape_identifier for sanitizing database inputs, and of course preg_match and preg_replace for all sorts of stuff.

Answer 2

Filters are used to sanitize input and output.
reference=> http://php.net/manual/en/filter.filters.sanitize.php