Daftar Isi

• ref EXPR

• ref

  Returns a non-empty string if EXPR is a reference, the emptystring otherwise. If EXPRis not specified, $_ will be used. The value returned depends on thetype 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 packagename is returned instead. You can think of ref as a typeof operator.

   if (ref($r) eq "HASH") {
   
   print "r is a reference to a hash.\n";
   
   }
   
   unless (ref($r)) {
   
   print "r is not a reference at all.\n";
   
   }
   

  The return value LVALUE indicates a reference to an lvalue that is nota variable. You get this from taking the reference of function calls likepos() or substr(). VSTRING is returned if the reference pointsto a version string.

  The result Regexp indicates that the argument is a regular expressionresulting from qr//.

  See also perlref.