diff options
Diffstat (limited to 'pod/perlobj.pod')
-rw-r--r-- | pod/perlobj.pod | 37 |
1 files changed, 13 insertions, 24 deletions
diff --git a/pod/perlobj.pod b/pod/perlobj.pod index 891ebe37f2..f427de7cde 100644 --- a/pod/perlobj.pod +++ b/pod/perlobj.pod @@ -373,18 +373,19 @@ are inherited by all other classes: C<isa> returns I<true> if its object is blessed into a subclass of C<CLASS> -You can also call C<UNIVERSAL::isa> as a subroutine with two arguments. -The first does not need to be an object or even a reference. This -allows you to check what a reference points to, or whether -something is a reference of a given type. Example +You can also call C<UNIVERSAL::isa> as a subroutine with two arguments. Of +course, this will do the wrong thing if someone has overridden C<isa> in a +class, so don't do it. - if(UNIVERSAL::isa($ref, 'ARRAY')) { - #... - } +If you need to determine whether you've received a valid invocant, use the +C<blessed> function from L<Scalar::Util>: -To determine if a reference is a blessed object, you can write + if (blessed($ref) && $ref->isa( 'Some::Class')) { + # ... + } - print "It's an object\n" if UNIVERSAL::isa($val, 'UNIVERSAL'); +C<blessed> returns the name of the package the argument has been +blessed into, or C<undef>. =item can(METHOD) @@ -392,21 +393,9 @@ C<can> checks to see if its object has a method called C<METHOD>, if it does then a reference to the sub is returned, if it does not then I<undef> is returned. -C<UNIVERSAL::can> can also be called as a subroutine with two arguments. -It'll always return I<undef> if its first argument isn't an object or a -class name. So here's another way to check if a reference is a -blessed object - - print "It's still an object\n" if UNIVERSAL::can($val, 'can'); - -You can also use the C<blessed> function of Scalar::Util: - - use Scalar::Util 'blessed'; - - my $blessing = blessed $suspected_object; - -C<blessed> returns the name of the package the argument has been -blessed into, or C<undef>. +C<UNIVERSAL::can> can also be called as a subroutine with two arguments. It'll +always return I<undef> if its first argument isn't an object or a class name. +The same caveats for calling C<UNIVERSAL::isa> directly apply here, too. =item VERSION( [NEED] ) |