On page 457 of the book First Heard - Servlet and Jsp (2nd edition) it says the following.
If the attribute named by "var" does not exist, it is created, more only if value is not null
Not what the tests say, see:
Another person sso displays, ie, even if there is an attribute it is created, why? the book is wrong?
On page 455 of the book First Heard - Servlet and Jsp (2nd edition) it says the following.
If the value of c: set evaluates to null, the attribute is removed, if you do not specify a scope, he will begin looking at the page, request, session, application
jsp the result is blank, the value will not appear Fulano 2
That is not how I put the value, it evaluates to null, ie it removes the attribute person, starting from the scope of the search page to the application.
He should just remove the request, should not also remove the session, anyone know why this happens?