- $array = delete_undef_values(['A','',undef,false])
+ > *Note:*
+ Since Puppet 4.0.0 the equivalent can be performed with the built-in
+ [`filter`](https://puppet.com/docs/puppet/latest/function.html#filter) function:
+ $array.filter |$val| { $val =~ NotUndef }
+ $hash.filter |$key, $val| { $val =~ NotUndef }