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Groups > comp.lang.java.programmer > #8576
| Date | 2011-10-05 10:21 -0700 |
|---|---|
| From | Patricia Shanahan <pats@acm.org> |
| Newsgroups | comp.lang.java.programmer |
| Subject | Re: I don't why I get 'not a statement' error in the following code... |
| References | <de7d2141-f562-452d-b754-46cab58ef211@d18g2000yql.googlegroups.com> <ut2dnZcFmYX1zBbTnZ2dnUVZ_q2dnZ2d@earthlink.com> <7de755e8-3339-4c3c-95a0-03d0e4aab701@5g2000yqo.googlegroups.com> <peCdnd3vqM_YdRbTnZ2dnUVZ_tmdnZ2d@earthlink.com> <bdc2e347-7d08-4b52-bfc2-cc17de9fd330@20g2000yqq.googlegroups.com> |
| Message-ID | <NNWdnfnEyse-DxHTnZ2dnUVZ_oadnZ2d@earthlink.com> (permalink) |
On 10/5/2011 8:13 AM, Chad wrote: > On Oct 4, 10:16 pm, Patricia Shanahan<p...@acm.org> wrote: >> On 10/4/2011 2:55 PM, Chad wrote: >> >> >> >> >> >>> On Oct 4, 11:33 am, Patricia Shanahan<p...@acm.org> wrote: >>>> On 10/4/2011 11:16 AM, Chad wrote: >>>> ... >> >>>>> I don't get why 'Test.x;' in main() isn't a variable. The expression >>>>> 'Test.x' ends with a semicolon. So I just assumed it was a valid >>>>> statement. However, the java compiler tells me something different. >>>>> Ideas? Possible hints? >> >>>> See the JLS,http://java.sun.com/docs/books/jls/third_edition/html/statements.html... >> >>>> Only certain types of expressions can be turned into a statement by >>>> adding a semicolon. They all have at least potential for side-effects at >>>> the top level. >> >>>> May I ask why you need to execute Test.x without doing anything with the >>>> result? >> >>> I still don't see why this expression can't be turned into a >>> statement. >> >> Primarily, it is a matter of language definition, which is why I >> included a link to the Java Language Specification. >> >> Are you saying that you think it is valid according to the JLS, or are >> you saying that you do not understand why the Java designers decided not >> to permit it? >> > > I guess I don't understand why the Java designers decided not to > permit it. I think to reduce source code that is pure decoration, with no effect on the program as run. A Java implementation is allowed to optimize, as long as it keeps both any results that are used and any side effects. Evaluating Test.x has no side effects, and the result is dead, so the entire statement would be dead code which the implementation can, and ideally should, firmly ignore. Patricia
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I don't why I get 'not a statement' error in the following code... Chad <cdalten@gmail.com> - 2011-10-04 11:16 -0700
Re: I don't why I get 'not a statement' error in the following code... Patricia Shanahan <pats@acm.org> - 2011-10-04 11:33 -0700
Re: I don't why I get 'not a statement' error in the following code... Chad <cdalten@gmail.com> - 2011-10-04 11:43 -0700
Re: I don't why I get 'not a statement' error in the following code... markspace <-@.> - 2011-10-04 12:14 -0700
Re: I don't why I get 'not a statement' error in the following code... Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2011-10-04 12:20 -0700
Re: I don't why I get 'not a statement' error in the following code... Chad <cdalten@gmail.com> - 2011-10-04 14:55 -0700
Re: I don't why I get 'not a statement' error in the following code... Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2011-10-04 15:09 -0700
Re: I don't why I get 'not a statement' error in the following code... Chad <cdalten@gmail.com> - 2011-10-04 15:11 -0700
Re: I don't why I get 'not a statement' error in the following code... Daniel Pitts <newsgroup.nospam@virtualinfinity.net> - 2011-10-04 17:30 -0700
Re: I don't why I get 'not a statement' error in the following code... Stanimir Stamenkov <s7an10@netscape.net> - 2011-10-05 01:19 +0300
Re: I don't why I get 'not a statement' error in the following code... Patricia Shanahan <pats@acm.org> - 2011-10-04 22:16 -0700
Re: I don't why I get 'not a statement' error in the following code... Chad <cdalten@gmail.com> - 2011-10-05 08:13 -0700
Re: I don't why I get 'not a statement' error in the following code... Patricia Shanahan <pats@acm.org> - 2011-10-05 10:21 -0700
Re: I don't why I get 'not a statement' error in the following code... Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-10-05 20:43 -0400
Re: I don't why I get 'not a statement' error in the following code... markspace <-@.> - 2011-10-05 19:36 -0700
Re: I don't why I get 'not a statement' error in the following code... Lew <lewbloch@gmail.com> - 2011-10-05 19:43 -0700
Re: I don't why I get 'not a statement' error in the following code... Roedy Green <see_website@mindprod.com.invalid> - 2011-10-05 12:00 -0700
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