% perl -le '$b=[1..4]; $#a=$b; print $#{$#a}'
3

##</code><code>##

% perl -le '$b=[1..4]; $#a=$b; print @{$#a}; push @$b, 5; print @{$#a}'
1234
12345

##</code><code>##

% perl -le '$b=[1..4]; $#a=$b; print $#a->[2]'
3

% perl -le '$b=\"foo"; $#a=$b; print ${$#a}'
foo

% perl -le '$b={foo=>1}; $#a=$b; print keys %{$#a}'
foo

##</code><code>##

% perl -le 'sub foo{"foo"} $b=bless[]; $#a=$b; print $#a->foo'
Can't call method "foo" without a package or object reference at -e line 1.

##</code><code>##

% perl -le '$b=[1..4]; $#a=$b; print ref $#a'
[nothing]

##</code><code>##

% perl -le '$b=[1..4]; $#a=$b; $x=$#a; print @$x'
[nothing]

##</code><code>##

% perl -le '$b=[1..4]; $#a=$b; $x=$#a; print @{$#a}' 
[nothing]

##</code><code>##

#/usr/bin/perl -l
my@a=qw[just another perl hacker];$#a=\@a;
print "@{$#{$#{$#{$#{$#{$#{$#{$#a}}}}}}}}"