Re: Using an undefined value as a hashref

[itub]

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 .

[ikegami]

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='', ...);

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?

[phaylon]

I'd guess it is because my returns the generated variable.

[talexb]

Wow.

Thank you. I didn't know that. I've learned a new thing today. Cool.