Below I compare two scalars $temp3 which contains the number 27 and $user_id which contains the number 0. When I compare the two I get the HASH reference error. Displayed under the code below is the local $SIG{'__DIE__'} output where I dump values of variables used.The dump shows no undefined HASH reference. Infact where the script dies I am only testing numeric values. 

1515    $ref = @{$no_call_requested_days->{$today_int}}[$i];
1516    $temp2 = $ref->{'employee_id'};
1517
1518    $temp3 = $user_id;
1519    if ($temp3 eq $user_id) {}
1520    if ($temp3 eq $temp2) {}
1521
1522    $temp3 = $temp2;
1523
1524
1525    if ($temp3 eq $temp2) {}
1526
1527
1528    if ($temp3 eq $user_id) # $temp3 = ref->{'employee_id'}
1529    {
1530        ...

[download]



THIS IS THE LOCAL $SIG{'__DIE__'} PRINTOUT
Can't use an undefined value as a HASH reference at /usr/local/www/cgi
+-bin/kapc/md2/display_md_calendar.cgi line 1528.
$user_id == 0
ref($user_id) ==
$temp2 == 27
ref($temp2) ==
$temp3 == 27
ref($temp3) ==
$ref == HASH(0x8390bf0)
ref($ref) == HASH
$ref->{'employee_id'} == 27
$ref->{'type'} == Routine
---
$i == 0
$today_int == 1041483600
$no_call_requested_days == HASH(0x837ded0)
\$no_call_requested_days->{$today_int} == ARRAY(0x8390c38)
scalar(@{$no_call_requested_days->{$today_int}}) == 2
@{$no_call_requested_days->{$today_int}}[$i] == HASH(0x8390bf0)
${@{$no_call_requested_days->{$today_int}}[$i]}->{employee_id} == 27
%{@{$no_call_requested_days->{$today_int}}[$i]}->{type} == Routine
---

[download]

In reply to Can't use an undefined value as a HASH reference by Anonymous Monk

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