##
>>> a=[1,2,3]
>>> b=a
>>> b[0]=42
>>> a[0]
42
####
DB<104> $a=[1,2,3]
=> [1, 2, 3]
DB<105> $b=$a
=> [1, 2, 3]
DB<106> $b->[0]=42
=> 42
DB<107> $a->[0] # original changed
=> 42
####
DB<108> \@a
=> [1, 2, 3]
DB<109> $b=\@a
=> [1, 2, 3]
DB<110> $b->[0]=666
=> 666
DB<111> $a[0] # original changed
=> 666
####
DB<112> @$b
=> (666, 2, 3) # now a (list) not an [array-ref]