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Re: Blocks for scope control

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  Arved Sandstrom wrote:
> See
> http://stackoverflow.com/questions/1563030/anonymous-code-blocks-in-java
> for a general discussion.
>
> I'm talking specifically about the block by itself: a pair of braces by
> themselves, enclosing some code in a method. On occasion I do run across
> situations where a judicious use of such a block inside a method, to
> restrict variable visibility, is handy.
>
> I almost never see anyone else using these things this way. A block in a
> method always seems to be associated with a control construct or
> exception handling. As any number of references point out, you wouldn't
> expect to see many usages of local blocks, mainly because 99 times out
> of 100 that situation is probably handled best by a new method. But in
> my years of looking at Java it occurs to me that I barely see any use of
> this at all...even where it wouldn't be a bad idea.
>
> Any thoughts?

You see it standardly in initialization blocks, especially static, though I 
often (more often than not) find myself refactoring static initialization 
blocks to private static methods.  For instance initialization they're 
extremely useful for blocks that multiple constructors must share.

Within methods I use them as well, to enforce temporariness of variables. 
This is very handy to prevent re-use of a variable whose usefulness has 
expired.  The need is rare, but like the legendary left-handed stembolt, if 
you don't have it when you need it, that's a worry.

This idiom is also valid in other languages (e.g., C).

Calling such code blocks "anonymous" doesn't make sense.  Code blocks aren't 
named in the first place.

There are many, many idioms in Java that are woefully underused.  'assert' is 
the prime example.  People don't understand it, even excoriate it (strange as 
that seems), and it's been around about a decade, since Java 1.4.  Lack of use 
does not equate to lack of value.

-- 
Lew
Honi soit qui mal y pense.
http://upload.wikimedia.org/wikipedia/commons/c/cf/Friz.jpg

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Blocks for scope control Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-01-15 11:50 -0400
  Re: Blocks for scope control Robert Klemme <shortcutter@googlemail.com> - 2012-01-15 17:10 +0100
  Re: Blocks for scope control Robert Klemme <shortcutter@googlemail.com> - 2012-01-15 17:32 +0100
    Re: Blocks for scope control Lew <noone@lewscanon.com> - 2012-01-15 11:21 -0800
    Re: Blocks for scope control Robert Klemme <shortcutter@googlemail.com> - 2012-01-16 07:59 +0100
  Re: Blocks for scope control markspace <-@.> - 2012-01-15 09:57 -0800
    Re: Blocks for scope control Lew <noone@lewscanon.com> - 2012-01-15 11:28 -0800
  Re: Blocks for scope control Lew <noone@lewscanon.com> - 2012-01-15 11:00 -0800
    Re: Blocks for scope control Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-01-15 17:49 -0400
      Re: Blocks for scope control Lew <noone@lewscanon.com> - 2012-01-15 15:45 -0800
        Re: Blocks for scope control Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-01-19 21:54 -0400
          Re: Blocks for scope control Robert Klemme <shortcutter@googlemail.com> - 2012-01-20 08:41 +0100
            Re: Blocks for scope control Lew <noone@lewscanon.com> - 2012-01-20 15:24 -0800
            Re: Blocks for scope control Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-01-20 19:30 -0400
              Re: Blocks for scope control Lew <noone@lewscanon.com> - 2012-01-20 15:54 -0800
      Re: Blocks for scope control Robert Klemme <shortcutter@googlemail.com> - 2012-01-16 07:55 +0100
        Re: Blocks for scope control Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-01-19 21:16 -0400
          Re: Blocks for scope control Robert Klemme <shortcutter@googlemail.com> - 2012-01-21 13:25 +0100
            Re: Blocks for scope control Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2012-01-21 10:41 -0400
              Re: Blocks for scope control Robert Klemme <shortcutter@googlemail.com> - 2012-01-22 13:03 +0100
  Re: Blocks for scope control Roedy Green <see_website@mindprod.com.invalid> - 2012-01-16 06:09 -0800
    Re: Blocks for scope control Henk van Voorthuijsen <voorth@xs4all.nl> - 2012-01-16 07:03 -0800
  Re: Blocks for scope control Arne Vajhøj <arne@vajhoej.dk> - 2012-01-17 18:43 -0500
  Re: Blocks for scope control Lew <noone@lewscanon.com> - 2012-01-20 11:05 -0800
  Re: Blocks for scope control Gene Wirchenko <genew@ocis.net> - 2012-01-20 12:11 -0800
  Re: Blocks for scope control Arne Vajhøj <arne@vajhoej.dk> - 2012-02-06 21:24 -0500

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