$ perl -E '
    my $x = 5;
    say $x;
    my $y = \$x;
    say $y;
    say $$y;
    $$y += 3;
    say $x;
'
5
SCALAR(0x60008a1c8)
5
8

##</code><code>##

$ perl -E 'my $x = 5; say $x; my $y = \\\\$x; $$$$$y += 3; say $x'
5
8

##</code><code>##

$ perl -E 'say for \(qw{1 2 3})'
SCALAR(0x60008a730)
SCALAR(0x60008a7d8)
SCALAR(0x60008a748)

##</code><code>##

$ perl -E 'my @x = qw{1 2 3}; say for @x; my $y = \@x; say $y'
1
2
3
ARRAY(0x60008a8e8)

##</code><code>##

$ perl -E 'my @x = qw{1 2 3}; say for @x; my $y = \@x; say $y; say for @$y'
1
2
3
ARRAY(0x60008a828)
1
2
3

##</code><code>##

$ perl -E 'my @x = qw{1 2 3}; say for @x; my $y = \\@x; say $y'
1
2
3
REF(0x600003e80)

##</code><code>##

$ perl -E 'my @x = qw{1 2 3}; say for @x; my $y = \\@x; say $y; say $$y; say for @$$y'
1
2
3
REF(0x600003e80)
ARRAY(0x60008a868)
1
2
3

##</code><code>##

$ alias perle
alias perle='perl -Mstrict -Mwarnings -Mautodie=:all -MCarp::Always -E'

##</code><code>##

$ perl -E '$x =5'

$ perle '$x =5'
Global symbol "$x" requires explicit package name (did you forget to declare "my $x"?) ...

$ perl -E 'my $x = 5; say @$x'

$ perle 'my $x = 5; say @$x'
Can't use string ("5") as an ARRAY ref while "strict refs" in use ...