in reply to Re^3: RFC: Tutorial: use strict; now what!?
in thread RFC: Tutorial: use strict; now what!?

$foo = 23;
$soft = 'foo'; # soft reference
$hard = \$foo; # hard reference
print "soft=$$soft, hard=$$hard\n";

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A soft reference holds a variable's name, while a hard reference holds its memory address. When you dereference a soft reference, you search for a name in the symbol table. When you dereference a hard reference, you fetch the variable at that address.

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Re^5: RFC: Tutorial: use strict; now what!?
by tangent (Parson) on Feb 09, 2012 at 16:52 UTC
    Thanks for explaining, I didn't know you could do that. BTW when I run that I get "soft=, hard=23"
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      Are you running exactly that program? What version of Perl? This is what I get: 
      $ cat foo2.pl
$foo = 23;
$soft = 'foo';
$hard = \$foo;
print "soft=$$soft, hard=$$hard\n";
$ perl foo2.pl
soft=23, hard=23
$ perl -v

This is perl, v5.10.1 (*) built for i686-cygwin-thread-multi-64int

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        I did change it slightly by adding my (couldn't help myself)
        
user$ cat foo2.pl
my $foo = 23;
my $soft = 'foo'; # soft reference
my $hard = \$foo; # hard reference
print "soft=$$soft, hard=$$hard\n";
user$ perl foo2.pl
soft=, hard=23
user$ perl -v

This is perl 5, version 14, subversion 1 (v5.14.1)
built for darwin-2level

user$ cat foo3.pl
$foo = 23;
$soft = 'foo'; # soft reference
$hard = \$foo; # hard reference
print "soft=$$soft, hard=$$hard\n";
user$ perl foo3.pl
soft=23, hard=23

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        I think I've learnt something about 'my' too!
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