Re: How to check if a function reference is valid or not?

[John W . Krahn]

On Wednesday 28 November 2007 02:15, howa wrote:
>
> sub abc {
>       print 'abc';
> }
>
> my $f1 = \&abc;
> my $f2 = \&abcee;
>
> print $f1; # return CODE(0x..)
> print $f2; # also return CODE(0x..)
>
> $f1->();
> $f2->();
>
> How do I know if $f2 is a valid function reference, without actual
> calling it?


$ perl -le'
sub abc {
         print 'abc';
}

my $f1 = \&abc;
my $f2 = \&abcee;

print "\$f1 ", defined &$f1 ? "exists" : "does not exist";
print "\$f2 ", defined &$f2 ? "exists" : "does not exist";

$f1->();
$f2->();
'
$f1 exists
$f2 does not exist
Undefined subroutine &main::abcee called at -e line 13.



John
-- 
use Perl;
program
fulfillment

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