Selecting a random key from a hash

Question

How do you select a random hash key? For my Flash+Perl card game I\'m trying to pick a random card from a hash where keys are: \"6 spades\", \"6 clubs\", etc. like this:

Answer 1

Get random value from %hash

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1. Store the keys of your %hash in @hash_keys.
2. generate a random number between 0 and the length of @hash_keys
3. get the random entry from @hash_keys
4. use the acquired key to get your random value from %hash

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Example snippet:

my %hash = ( 
  'stack' => 'overflow',
  'face'  => 'book',
  'inter' => 'net'
);

## ALTERNATIVE 1 ##
my @hash_keys    = keys %hash;

my $random_key   = $hash_keys[rand @hash_keys];
my $random_value = $hash{$random_key};

## ALTERNATIVE 2 ##
my $random_val_2 = (%hash)[1+2*int rand keys%hash]; # TIMTOWTDI

## ALTERNATIVE 3 ##
my $random_val_3 = [@_=%hash]->[1|rand@_];          # TIMTOWTDI

Answer 2

Here's another way (demonstrating how to pick a random element from a list of unknown length):

my $cards;
my $chosen;
while ( my $card = each %{$user->{HAND}} ) {
    $chosen = $card if rand(++$cards) < 1;
}

Answer 3

Somewhat more concise:

my $random_value = $hash{(keys %hash)[rand keys %hash]};