urlencode - In a URL, should spaces be encoded using %20 or +?

Question

This question already has answers here:

Answer 1

Form data (for GET or POST) is usually encoded as application/x-www-form-urlencoded: this specifies + for spaces.

URLs are encoded as RFC 1738 which specifies %20.

In theory I think you should have %20 before the ? and + after:

example.com/foo%20bar?foo+bar