In list context, returns a list consisting of all the values of the named hash. In Perl 5.12 or later only, will also return a list of the values of an array; prior to that release, attempting to use an array argument will produce a syntax error. In scalar context, returns the number of values.
Hash entries are returned in an apparently random order. The actual random order is specific to a given hash; the exact same series of operations on two hashes may result in a different order for each hash. Any insertion into the hash may change the order, as will any deletion, with the exception that the most recent key returned by each
or keys
may be deleted without changing the order. So long as a given hash is unmodified you may rely on keys
, values
and each
to repeatedly return the same order as each other. See "Algorithmic Complexity Attacks" in perlsec for details on why hash order is randomized. Aside from the guarantees provided here the exact details of Perl's hash algorithm and the hash traversal order are subject to change in any release of Perl. Tied hashes may behave differently to Perl's hashes with respect to changes in order on insertion and deletion of items.
As a side effect, calling values() resets the HASH or ARRAY's internal iterator, see "each". (In particular, calling values() in void context resets the iterator with no other overhead. Apart from resetting the iterator, values @array
in list context is the same as plain @array
. (We recommend that you use void context keys @array
for this, but reasoned that taking values @array
out would require more documentation than leaving it in.)
Note that the values are not copied, which means modifying them will modify the contents of the hash:
for (values %hash) { s/foo/bar/g } # modifies %hash values
for (@hash{keys %hash}) { s/foo/bar/g } # same
Starting with Perl 5.14, values
can take a scalar EXPR, which must hold a reference to an unblessed hash or array. The argument will be dereferenced automatically. This aspect of values
is considered highly experimental. The exact behaviour may change in a future version of Perl.
for (values $hashref) { ... }
for (values $obj->get_arrayref) { ... }
To avoid confusing would-be users of your code who are running earlier versions of Perl with mysterious syntax errors, put this sort of thing at the top of your file to signal that your code will work only on Perls of a recent vintage:
use 5.012; # so keys/values/each work on arrays
use 5.014; # so keys/values/each work on scalars (experimental)
See also keys
, each
, and sort
.