MultiDimensional array Input to Single array in Perl

I’ve the below Input and the expected output.

Input : [undef,[0,1],2]
Expected Output : [0,1,2]

Code I’ve written:

use Data::Dumper;
my $input=[undef,[0,1],2];
my @arr=@{$input};
@arr = grep {defined} @arr;
my @arrnew;
foreach my $value (@arr){
  if (ref $value    eq 'ARRAY') {
    push @arrnew,@{$value};
  } else {
    push @arrnew,$value;
  }
}
print Dumper(@arrnew);

Question:
Although, this gives me the correct output, would like to know if any simpler way of doing this in perl.

>Solution :

You can roll it all into a single expression using map and grep.

use strict;
use warnings;

my $foo = [undef,[0,1],2];
my @bar = map { ref eq 'ARRAY' ? @$_ : $_ } grep defined, @$foo;

The map acts like your foreach loop and produces a new list on the way out, which gets assigned to a new array @bar. The grep you had already used, but I’ve changed it to use expression syntax rather than block syntax.

Note this only works for one level of depths.