Re^2: Sometimes undef is initialized and sometimes not when hash values are fed to grep

Here two or three workarounds (can't test the latter)

    
use utf8;
use strict;
use warnings;

use Data::Dumper;

my %h = (a => 'alfa', b => 'beta'); 



print "\n\nWorkaround 1 \n";
print map { "\t>>$_<<\n" } "$h{a}", "$h{111}", "$h{b}"; 
print "after third:\n", Dumper(\%h); 



print "\n\nWorkaround 2 \n";
print map { "\t>>$h{$_}<<\n" } qw/a 222 b/; 
print "after third:\n", Dumper(\%h); 



# print "\n\nWorkaround 3 \n";
# no autovivification;
# print map { "\t>>$_<<\n" } $h{a}, $h{333}, $h{b}; 
# print "after third:\n", Dumper(\%h);
[download]

Cheers Rolf
_{(addicted to the Perl Programming Language :)

Wikisyntax for the Monastery
FootballPerl is like chess, only without the dice}

Comment on Re^2: Sometimes undef is initialized and sometimes not when hash values are fed to grep Download Code

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Re^3: Sometimes undef is initialized and sometimes not when hash values are fed to grep by haukex (Archbishop) on Feb 11, 2020 at 16:51 UTC
can't test the latter Unfortunately, that one doesn't work: `use warnings; use strict; use Data::Dumper; no autovivification; my %h = (a => 'alfa', b => 'beta'); print map { ">>$_<<\n" } $h{a}, $h{333}, $h{b}; print Dumper(\%h); __END__ Use of uninitialized value $_ in concatenation (.) or string at 111127 +86.pl line 8. >>alfa<< >><< >>beta<< $VAR1 = { '333' => undef, 'a' => 'alfa', 'b' => 'beta' };` [download]	[reply] [d/l]
Re^4: Sometimes undef is initialized and sometimes not when hash values are fed to grep by LanX (Saint) on Feb 11, 2020 at 16:54 UTC
ugh .... :/ But I seem to remember that this glitch was also mentioned in the last thread. Cheers Rolf _{(addicted to the Perl Programming Language :) Wikisyntax for the Monastery FootballPerl is like chess, only without the dice}	[reply]