Perl has three data structures: scalars, normal arrays --
also known as lists -- of scalars, and associative arrays of scalars,
known as ``hashes''. Normal arrays are indexed by number, starting with
0
. Hash arrays are
indexed by scalars. As mentioned before, scalar values are always named
with $, even when referring to a scalar that is part of an
array or hash, but entire arrays or array slices are denoted
by @. Analog to entire arrays, entire hashes are denoted
by %.
Every variable type has its own namespace which means
that $var, @var, and %var are three
different variables. One advantage is that
conflicts with reserved words are unlikely due to those three leading
chars.