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Re: Does perl sub using stack and possible to crash?

by Corion (Pope)
on Jan 17, 2013 at 10:13 UTC ( #1013744=note: print w/ replies, xml ) Need Help??


in reply to Does perl sub using stack and possible to crash?

Global variables are global, and @_ are aliases. This is easily replicated and tested with the following code (your while loop will never terminate so I used a for loop instead):

#!perl -w use strict; use Data::Dumper; my @someNameArray = qw(foo bar baz); print Dumper \@someNameArray; for(@someNameArray){ print( "Before: $_\n" );# $_ correct frobnicate($_); print( "After : $_\n" );# $_ changed } print "Final:\n"; print Dumper \@someNameArray; sub frobnicate { $_[0] = "changed value from '$_[0]'"; }; __END__ $VAR1 = [ 'foo', 'bar', 'baz' ]; Before: foo After : changed value from 'foo' Before: bar After : changed value from 'bar' Before: baz After : changed value from 'baz' Final: $VAR1 = [ 'changed value from \'foo\'', 'changed value from \'bar\'', 'changed value from \'baz\'' ];

If you

I suggest to use a lexical iterator instead of $_, and don't have your callees change elements in @_. Using a lexical iterator prevents action at a distance from called subroutines. Using @_ will need more changes and information about $finder->isExist(...).


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