On Wednesday 24 July 2002 19:48, Aidas Kasparas wrote:
> You can not directly. Empty string and undef are identical for perl.
sorry, but this is wrong. "" is not the same as undef. The following
expressions are true:
my $empty = ""; my $undef;
$empty eq $undef (but issues a warning if -w is used)
$empty == $undef (dito)
defined $empty
But these return false:
defined $undef
$undef
$empty
(see also perldoc -f defined, perldoc -f exists)
> You could use following perl code:
>
> if (exists ${$cgi->param}{foo}) { ....
A 'defined' test would suffice. But 'exists' is fine, too, of course. "defined
<param:foo/>" could or could not work, depending on how the param taglib is
written. (it should work, I believe)
CU
J�rg
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