hi,
i'm new to the perl, Can you please make me to understand the below piece of code which is part of example_5_1_unique.pl.

my @array = ( 3, 4, 1, 4, 7, 7, 4, 1, 3, 8 );
my %unordered;
@unordered{@array} = undef;

the explanation in the book is not clear to me..