p5pRT
commented
20 years ago From @hfuru
Created by @hfuru
About `foreach $var (...)'\, the perlsyn manual page says\,
If the variable was previously declared with "my"\, it uses that variable instead of the global one\,
That is not true. It creates a new lexical variable for the loop with the same name as the outside variable\, exactly as if one had written `foreach my $var'. If it was the same variable\, functions outside the loop would see the loop variable\, but they don't. They see the "my" variable which was declared outside the loop. I suppose that's what you mean with this addition to the above text:
but it's still localized to the loop.
but that does not really make sense. That sounds like the value of the "outer" lexical variable would be saved\, and restored after the loop. That's how it works with non-lexical variables.
my $var = "original value"; foreach $var ("loop-value") { print "foreach: $var\, "; f(); } print "end: $var\n"; sub f { print "function: $var\n"; } --> foreach: loop-value\, function: original value end: original value
BTW\, I think this is a misfeature which should get a warning. If one has such a loop which intends the variable to be global\, inserting a `my' previously in the code silently breaks the loop even though that new `my' variable isn't actually used in the loop. And there is no need for this feature since one can just say `foreach my $var' instead of `foreach $var'.
Migrated from rt.perl.org#28396 (status was 'open')
Searchable as RT28396$