hoopajoo.net | Curly braces and hashes

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Curly braces are used to create and access hash references. To create a normal, pre-populated hash, you might do this:

%myhash = (
   key1 => 'foo',
   key2 => 'bar'
);

And you have $myhash{key1} == 'foo', etc. The reference is acquired the same way as other references:

$hash_ref = \%myhash;

Hash refs use the {} along with the -> indirection operator for access like this:

$hash_ref -> { key1 } eq $myhash{ key1 };
$hash_ref -> { key2 } eq $myhash{ key2 };

Like with parenthesis and brackets, the curly braces can also be used to create a new hash reference without first creating the hash:

$hash_ref = {
  key1 => 'foo',
  key2 => 'bar'
};

Gives us the same hash as the first example.