Re: <identifier> expected error

From:
Lew <lewbloch@gmail.com>
Newsgroups:
comp.lang.java.help
Date:
Fri, 23 Sep 2011 17:56:25 -0700 (PDT)
Message-ID:
<20643304.220.1316825785758.JavaMail.geo-discussion-forums@prng5>
On Friday, September 23, 2011 5:10:11 PM UTC-7, Roedy Green wrote:

On Fri, 23 Sep 2011 12:10:58 -0700 (PDT), Lew <lewb...@gmail.com>
wrote, quoted or indirectly quoted someone who said :
 

 public interface NumList {
   void printArray();
 }

The coaching might have been phrased, "Method declarations must specify =

the return type, or 'void' if nothing is to be returned."

So I don't see "executable code" in the declaration, but "method defined=

 without return type". Either way it needs to be fixed.

 
I think "executable code" is one of several ways of interpreting the
error.
 
printArray();
 
From a bottom up point of view looks to it like an attempt to invoke
the method printArray() which may be undefined.
 
I agree though your interpretation of the error fits better with what
the author intended. Someday compilers might expend effort to decide
how to interpret errors. I wrote
http://mindprod.com/jgloss/compileerrormessages.html
to at least give programmers several alternate interpretations
to choose from.


Actually, your interpretation was an eye-opener for me, Roedy. You are exa=
ctly right - depending on how you approach the code it looks either like an=
 uncompilable declaration or an uncompilable command. It reminds me of the=
 figure/ground optical illusion that appears to be a crone or a young lady =
depending on how your brain organizes what you see.

This can be very useful to the OP - I infer that her difficulty was the con=
flation of the two concepts, declaration and invocation, hence the ambiguit=
y in the syntax. If true, the insight is that declaration occurs in a diff=
erent place from invocation. You declare a method in an interface (or abst=
ract class). You both declare it with the signature and define it with a m=
ethod body in the implementing class. You invoke a method from inside (the=
 body of) another method or constructor, which can be of the same class or =
another class.

Declare, define, invoke.

When you get further along in your studies, you'll see that as interface, i=
mplementing class, client method.

Good question and interesting insights from Roedy.

--
Lew

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