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Use of "return" in place of "last" (newbie question)?
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Use of "return" in place of "last" (newbie question)? Michael 03-09-2008
Posted by Michael on March 9, 2008, 10:34 am
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 I am new to perl, and I am wondering whether it is a bad thing to jump out
of a foreach loop with return. I have a function which searches for a
value in one of several arrays. If the value is found in any of them,
then the whole function may as well terminate. At the moment I am setting
a flag when the value is found, which stops execution of the later loops.
Would it be safe / stylistically sound to do away with the flag by using
"return" rather than "last". Example code follows.

TIA

sub example{

my $found;
$found = 0;

foreach $item (@list)
        {
         if ($value eq $item)
                {
                print ("found $value\n");
                $found = 1;
                last;
                }        
        }

... several other foreach loops follow in which the only thing which
differs is the name of the array which is "@list" above, and the test for
the flag.

return
}

Posted by Tad J McClellan on March 9, 2008, 11:16 am
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> I am new to perl, and I am wondering whether it is a bad thing to jump out
> of a foreach loop with return.


Yes it is a bad thing, because it will not work. :-)


> I have a function which searches for a
> value in one of several arrays. If the value is found in any of them,
> then the whole function may as well terminate.


Oh.

Using a return() to return from a subroutine is perfectly fine
(even if the return() is within a loop).


> Would it be safe / stylistically sound to do away with the flag by using
> "return" rather than "last".


Yes.


--
Tad McClellan
email: perl -le "print scalar reverse qq/moc.noitatibaher0cmdat/"

Posted by Michael on March 9, 2008, 12:58 pm
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On Sun, 09 Mar 2008 10:16:08 -0500, Tad J McClellan wrote:
<snip>
>
> Using a return() to return from a subroutine is perfectly fine (even if
> the return() is within a loop).
>
>> Would it be safe / stylistically sound to do away with the flag by
>> using "return" rather than "last".
>
> Yes.

Many thanks for the prompt and helpful response Tad.

/M


Posted by Jürgen Exner on March 9, 2008, 1:14 pm
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>I am new to perl, and I am wondering whether it is a bad thing to jump out
>of a foreach loop with return.

Technically it doesn't make a difference.

Stylistically it is a matter of which programming philosophy you are
following. For GOTOists it is standard operating procedure, for functional
programmers it is a sacrilege. Others are somewhere in between.

jue

Posted by Joost Diepenmaat on March 9, 2008, 1:23 pm
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>>I am new to perl, and I am wondering whether it is a bad thing to jump out
>>of a foreach loop with return.
>
> Technically it doesn't make a difference.
>
> Stylistically it is a matter of which programming philosophy you are
> following. For GOTOists it is standard operating procedure, for functional
> programmers it is a sacrilege. Others are somewhere in between.

Functional programmers don't use foreach either :-)

Personally, I think using a return statement generally leads to less
convoluted, clearer code.

--
Joost Diepenmaat | blog: http://joost.zeekat.nl/ | work: http://zeekat.nl/

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