Re: Case expression must be constant expression
Philipp wrote:
Roedy Green wrote:
On Thu, 22 Nov 2007 13:39:13 +0100, Philipp <sicsicsic@freesurf.ch>
wrote, quoted or indirectly quoted someone who said :
"Case expression must be constant expression", but as far as I can
see, the expression are constant.
By "constant", they don't mean final. they mean "known at compile
time". They mean literals or compile time constants.
See http://mindprod.com/jgloss/literal.html
http://mindprod.com/jgloss/constant.html
Hello
On your very clear and understandable page
http://mindprod.com/jgloss/constant.html (which IMHO is not the case of
the JLS), you write:
4. Instance Constants: <snip>
It is sometimes possible for an instance constant to be evaluated at
compile time. In that case it is treated like a literal, much like a
static compile-time constant.
Isn't this exactly the case of my example in the original post? Isn't it
an instance constant which can be evaluated at compile time?
Btw, I wanted to use a switch in my code, but due to these limitation
it's now a if/else stack...
Best regards
Phil
Just a note, have you considered using enums or even use a polymorphic
object instead of switch?
<http://virtualinfinity.net/wordpress/program-design/2007/10/22/using-enums-as-a-flyweight-pattern/>
In Object Oriented design, its considered a likely problem if you have a
switch statement (or a switch like construct). While there are *some*
times when a switch is appropriate, I've found that I haven't used a
switch statement once I understood the State, Strategy, and Flyweight
patterns.
As an aside more direct to your original post, is there a good reason to
make them *not* static final int?
--
Daniel Pitts' Tech Blog: <http://virtualinfinity.net/wordpress/>