each_key()
public
Calls block once for each key in hsh, passing the key as a parameter.
If no block is given, an enumerator is returned instead.
h = { "a" => 100, "b" => 200 }
h.each_key {|key| puts key }
produces:
a
b
static VALUE
rb_hash_each_key(VALUE hash)
{
RETURN_SIZED_ENUMERATOR(hash, 0, 0, hash_enum_size);
rb_hash_foreach(hash, each_key_i, 0);
return hash;
}