Re^2: why need my in a foreach loop?

Here's the difference:

use strict;
use warnings;
use 5.010;

our $foo = 'hello';

sub f {
   print("$foo\n");
}

for my $foo (qw( a b c )) {
   f();  
}

--output:--
hello
hello
hello
[download]

In ikegami's example, the my is omitted in the for loop, which causes the for loop to change the global variable $foo--and the subroutine prints the global $foo (i.e. the subroutine is a closure).

Comment on Re^2: why need my in a foreach loop? Download Code

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Re^3: why need my in a foreach loop? by ikegami (Patriarch) on Nov 28, 2010 at 23:23 UTC
the subroutine is a closure Backwards. It works because the subroutine doesn't capture package variables. If you switched `our` for `my` in my snippet, you'd have a closure, and you'd get a different result.	[reply] [d/l] [select]
Re^4: why need my in a foreach loop? by 7stud (Deacon) on Dec 02, 2010 at 03:46 UTC
Nice catch. If you switched our for my in my snippet, you'd have a closure, and you'd get a different result. Is that correct? Because the my variable would still be in scope, would the subroutine qualify as a closure? It's my understanding that a subroutine is a closure when it preserves a variable that has gone out of scope.	[reply]
Re^5: why need my in a foreach loop? by ikegami (Patriarch) on Dec 02, 2010 at 16:38 UTC
I don't know the precise definition if there is one. For practical purposes, I find it doesn't matter. Correction: In this case, the sub truly acts as a closure. If it didn't, it wouldn't matter if you used `our` or `my`.	[reply] [d/l] [select]