Reference Basic in Perl

Making References

References can be created in several ways.

By using the backslash operator on a variable, subroutine, or value. (This works much like the & (address-of) operator in C.) This typically creates another reference to a variable, because there's already a reference to the variable in the symbol table. But the symbol table reference might go away, and you'll still have the reference that the backslash returned. Here are some examples:

    $scalarref = \$foo;
    $arrayref  = \@ARGV;
    $hashref   = \%ENV;
    $coderef   = \&handler;
    $globref   = \*foo;

Using References

That's it for creating references. By now you're probably dying to
know how to use references to get back to your long-lost data. There
are several basic methods.

1. Anywhere you'd put an identifier (or chain of identifiers) as part of a
   

   variable or subroutine name, you can replace the identifier with a
   BLOCK returning a reference of the correct type. In other words, the
   previous examples could be written like this:
   

       $bar = ${$scalarref};
       push(@{$arrayref}, $filename);
       ${$arrayref}[0] = "January";
       ${$hashref}{"KEY"} = "VALUE";
       &{$coderef}(1,2,3);
       $globref->print("output\n");  # iff IO::Handle is loaded