in reply to To initialise or not to initialise?

kiat, another good question, one that I have thought about often. Here's where I'm at now. I no longer initialize with a value, unless that value is to be used immediately and/or it helps me read what I'm doing: 
my $ctr = 0;
for ( 0 .. 5 ) {
   if ($foo[$_] eq $bar) {
      $ctr++;
   }
}

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I have found there is a difference between: 
my $variable;

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and 
my $variable = "";

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or 
my $variable = 0;

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depending on usage. In summary, I don't think there can be a hard a fast rule. Like many things, it depends on context and the readibility you need.

—Brad
"Don't ever take a fence down until you know the reason it was put up. " G. K. Chesterton

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Re^2: To initialise or not to initialise?
by kiat (Vicar) on Jun 24, 2004 at 13:30 UTC
    Hi bradcathey,
    I have found there is a difference between:
    Do you mean the difference between being defined and undefined? 
    my $var1;
# not printed because $var1 is not defined
print "var1: $var1\n" if defined $var1;

my $var2 = '';
# printed with $var2 as an empty string
# output var2: 
print "var2: $var2\n" if defined $var2;

my $var3 = 0;
# printed with $var3 set to 0
# output var3: 0 
print "var3: $var3\n" if defined $var3;

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    cheers,
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[d/l]
      Precisely, thanks for clearing up the terminology. And I have to apologize for not being about to think of a good example, but I have found at times I need the undefined variable, as opposed to the defined, inferring a value.

      —Brad
      "Don't ever take a fence down until you know the reason it was put up. " G. K. Chesterton
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        Ah okay.

        I thought it might be something to do with concatenation at first, which also shows a subtle difference: 

        my $var1;
print $var1 .= 'r', "\n";
# prints r

my $var2 = '';
print $var2 .= 'r', "\n";
#prints r

my $var3 = 0;
print $var3 .= 'r', "\n";
#prints 0r

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        :)
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[d/l]

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