Asking An Object For It's Class

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

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Re: Asking An Object For It's Class by demerphq (Chancellor) on Aug 14, 2003 at 01:16 UTC
TMTOWTDI: `use Scalar::Util qw(blessed); if (my $class=blessed $foo) { print "Its an object of class $class\n"; } else { print "Its not an object\n"; }` [download] This has the advantage that you can discriminate a blessed reference from an un-blessed one safely, regardless as to what package name it has been blessed into, and avoids the painful filtering of unblessed references which requires overload::StrVal and regexes if you want to be thorough. There is also a function called reftype() which does the converse, telling you what the underlying type is and not what type its blessed into. Read more... (2 kB) `Testing '$Evil_Hash' ref :ARRAY U::isa :1 ->isa :1 StrVal :ARRAY=HASH(0x1abf1a8) blessed :ARRAY reftype :HASH refaddr :28045736 ----` [download] --- demerphq _{<Elian> And I do take a kind of perverse pleasure in having an OO assembly language...}	[reply] [d/l] [select]
Re: Asking An Object For It's Class by Limbic~Region (Chancellor) on Aug 13, 2003 at 22:54 UTC
Anonymous Monk, Unless there has been any hanky panky going on, I believe that a simple ref $object; should do what you want? If you suspect foul play or want to know the underlying type of an object, I would recommend reading this node. I found it quite enlightening. <headshake>`my $not_a_hash = bless [], 'HASH';`</headshake> Cheers - L~R	[reply] [d/l]
Re: Asking An Object For It's Class by shemp (Deacon) on Aug 13, 2003 at 22:57 UTC
Here's 2 approaches that may get you what you want. 1 is to ref() the variable, and it will tell you something about the object. `my $what_is_it = ref($unidentified_object);` [download] This may not return what you expect though, because most objects are of more than 1 type (they are whatever they were last bless()'ed as, and all of their parent class types). Someone else can certainly better explain exactly what ref() will return in various circumstances. A probably better options is to use UNIVERSAL::isa(), which all classes inherit. isa() allows you to ask an object if its a certain type: `if ( $u_o->isa("blah" ) ) { # do something } elsif ( $u_o->isa("something_else") ) { # do something else } ...` [download] Depending on what you're trying to do, one or the other should probably do what you need.	[reply] [d/l] [select]
Re: Asking An Object For It's Class by larsen (Parson) on Aug 13, 2003 at 22:55 UTC
From `perldoc -f ref` If the referenced object has been blessed into a package, then that package name is returned instead. You can think of "ref" as a "typeof" operator. So it's `my $class = ref( $unidentified_object );` [download]	[reply] [d/l]
Re: Asking An Object For It's Class by particle (Vicar) on Aug 13, 2003 at 22:54 UTC
`perldoc -f ref` ~Particle accelerates	[reply] [d/l]
Re: Asking An Object For It's Class by adrianh (Chancellor) on Aug 13, 2003 at 22:55 UTC
Use ref `$class = ref($unidentifed_object)` [download]	[reply] [d/l]