Re^4: Checking for blank string

> so the warning must be coming from some other undef value somewhere else in your code

Maybe the key doesn't exist in the hash at all?

($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,
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Re^5: Checking for blank string by haukex (Archbishop) on Sep 26, 2016 at 10:15 UTC
Hi choroba, Maybe the key doesn't exist in the hash at all? The defined check would still catch that and there wouldn't be a warning. And if `$cell` was `undef`, the warning would be "Use of uninitialized value $cell in hash element", not "Use of uninitialized value $data in string eq" as the OP posted here. `use warnings; use strict; my $sheet = { 'X92' => '', 'AA571' => '0.00', 'AA842' => '0.00', 'B6' => '0', 'E47' => 'SRAM (ssbw)', 'M83' => '', 'X55' => undef, 'B29' => '0' }; sub test { my $cell = shift; if(defined $sheet->{$cell} && length($sheet->{$cell})) { print "Yes\n" } else { print "No\n" } } test(undef); test('A12'); test('X55'); test('M83'); test('B29'); test('E47'); __END__ Use of uninitialized value $cell in hash element at ... No No No No Yes Yes` [download] Regards, -- Hauke D	[reply] [d/l] [select]

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Re^5: Checking for blank string
by haukex (Archbishop) on Sep 26, 2016 at 10:15 UTC

Hi choroba,

Maybe the key doesn't exist in the hash at all?

The defined check would still catch that and there wouldn't be a warning. And if $cell was undef, the warning would be "Use of uninitialized value $cell in hash element", not "Use of uninitialized value $data in string eq" as the OP posted here.

use warnings;
use strict;

my $sheet = {
    'X92' => '',
    'AA571' => '0.00',
    'AA842' => '0.00',
    'B6' => '0',
    'E47' => 'SRAM (ssbw)',
    'M83' => '',
    'X55' => undef,
    'B29' => '0' };

sub test {
    my $cell = shift;
    if(defined $sheet->{$cell} && length($sheet->{$cell}))
        { print "Yes\n" }
    else { print "No\n" }
}

test(undef);
test('A12');
test('X55');
test('M83');
test('B29');
test('E47');

__END__

Use of uninitialized value $cell in hash element at ...
No
No
No
No
Yes
Yes
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Regards,
-- Hauke D

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