Re: Using an undefined value as a hashref

The trick is that variables created by "my" are not available until the next statement, as documented in perlsub:

The declared variable is not introduced (is not visible)
until after the current statement. Thus,

    my $x = $x;

can be used to initialize a new $x with the value of the 
old $x, and the expression

    my $x = 123 and $x == 123

is false unless the old $x happened to have the value 123 .
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Comment on Re: Using an undefined value as a hashref Download Code

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Re^2: Using an undefined value as a hashref by ikegami (Patriarch) on Sep 10, 2005 at 04:04 UTC
I don't think that's totally true. The variable name is not available until the next statement, but the variable itself is. Otherwise, I don't see how the following two statements would work: `open(my $fh, ...); read($fh, my $buf='', ...);` [download] I think the problem here is that you can't auto-vivify the lvalue returned by `my`. Can anyone confirm or deny any of this?	[reply] [d/l] [select]
Re^3: Using an undefined value as a hashref by phaylon (Curate) on Sep 10, 2005 at 20:13 UTC
I'd guess it is because my returns the generated variable. Ordinary morality is for ordinary people. -- Aleister Crowley	[reply]
Re^2: Using an undefined value as a hashref by talexb (Chancellor) on Sep 09, 2005 at 21:16 UTC
Wow. Thank you. I didn't know that. I've learned a new thing today. Cool. Alex / talexb / Toronto "Groklaw is the open-source mentality applied to legal research" ~ Linus Torvalds	[reply]