Returns a non-empty string if EXPR is a reference, the empty
string otherwise. If EXPR
is not specified, $_
will be used. The value returned depends on the
type of thing the reference is a reference to.
Builtin types include:
- SCALAR
- ARRAY
- HASH
- CODE
- REF
- GLOB
- LVALUE
- FORMAT
- IO
- VSTRING
- Regexp
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.
The return value LVALUE
indicates a reference to an lvalue that is not
a variable. You get this from taking the reference of function calls like
pos()
or substr()
. VSTRING
is returned if the reference points
to a version string.
The result Regexp
indicates that the argument is a regular expression
resulting from qr//
.
See also perlref.