I have a piece of code that does stuff randomly. Using rand (which is sufficiently random for my purposes). So that's on purpose. However, I want to be able to test certain scenarios specifically (code coverage, sorta). So I figured that since all random generation goes through a single _random function, I could just easily put a debug-hack in there that would allow me to specify the random numbers. However, I seem to get some wierd behaviour in the debug code - it's not critical, but I'm curious as to how to quash it.

The problem is given by the code below. I'm sure I could get this simpler, but I was just happy to reproduce it at all (I fought with it for about 5 minutes until I realised that, duh, the warning would only come up if I turned on warnings...).

The warning is: "Use of uninitialized value in list assignment at ./a.pl line 13."

use strict;
use warnings;

my $foo = '1Z1';
$ENV{Z1Z1} = '3,2,1';

for (1..5)
{
    my $x = '?';
    if ($ENV{'Z' . uc $foo})
    {
        ($x, $ENV{'Z' . uc $foo}) = split /,/, $ENV{'Z' . uc $foo}, 2;
    }
    print $x, $/;
}

[download]

Output:

3
2
Use of uninitialized value in list assignment at ./a.pl line 13.
1
?
?

[download]

Expected/desired output: everything except the warning.

Ideally, this would be done without "no warnings" inside the assignment. If that's not possible, I'll just stick in that pragma and be done with it - I just don't like avoiding warnings or strict unless I know that it's the only way to do what I want to do, and I'm not that confident here yet.

Thanks,

In reply to Uninitialised value in list assignment by Tanktalus

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