June 2002
Beginner
759 pages
80h 42m
English
isa
$io= $fd->isa(type)
Returns true if the reference is blessed into package
type or inherits from that package. Can
be called as a static or object method call, or as a
subroutine:
UNIVERSAL::isa(val,type)
Returns true if the first argument is a reference and either of the following is true:
val is a blessed reference
and is blessed into package type or
inherits from package type.
val is a reference to a
type of Perl variable (e.g.,
'HASH').