Find key name in hash with only one key?

Question

If I have a hash

my %h = (
    secret => 1;
);

and I know that is only is one key in the hash, but I don\'t know what it is called.

Answer 1

I do not believe it is necessary to use the keys function.

my ($key) = %h;

or

my $key = (%h)[0];

The hash inside the parens will be expanded to a list, then we can simply take the first element of that list, which is the key.