OK, so for arrays and hashes there is no need. This is just about scalars then.
I certainly don't advocate initialization for it's own sake simply to shutup warnings about uninitialized variables.

An idiom I like to use in subs where something like: 
sub foo {
  my $retval = 0;
  <... lots of code here ...>
  return $retval; # This is the only return in the sub
}

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I like to use this for several reasons

1) It's guaranteed that the sub will always return a value.
2) There is a single entry/exit point. Apart from it being simple, I know that this makes it easier for compilers/interpreters to prove certain things about your code. Can't say I know if it will make any difference whatsoever in Perl, but it often does in C-like languages.
3) The initial value of 0 is assumed to be the failure case, putting the burden of 'proof' to set $retval properly. Hope to see a failure case quicker this way.

When possible, I also prefer to see code more like: 
...
my $whatever = some_sub();

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I find the 'classic C' style of declaring lots of variables at the top of your routine, then using them in the body, to be harder to follow. e.g.: 
my $var1;
my $var2;
my $var3;
my @list;
my %hash;
...

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Worse if they're all global! I don't like jumping back and forth, or wondering where variables got their values (or what they were initialized as/from). Arguably if the code was done well enough in the first place it would already be pretty short and there would be no problem, but unfortunately I see this all the time. IMO it's more error-prone. If that's what you mean when you said "declare variables to minimize their scope" then I agree.

In reply to Re^2: Use of uninitialized variables? by Zadeh
in thread Use of uninitialized variables? by Zadeh

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