I have a box of a dozen doughnuts. I want to eat three of them, and still have a full box with a dozen when I'm done.

Solution? You need another box. ;)

In Perl, you need two arrays; one is the original, and one will be the copy, on which you can perform whatever manipulations you wish, without affecting the original.

my @array = qw/one two three four five/;
my @copy  = @array;

shift @copy;

print "Original: @array\n";
print "Copy:     @copy\n";
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There are infinite other strategies, but your question is vague enough to make it impossible to focus on which strategy would be optimal.