Perl

Extract all the elements that are numbers in an array

Difficulty: unrated

Source: bregman-arie/devops-exercises by Arie Bregman

Answer

my @array = ('a', 1, 'b', 2, 'c', 3);
my @numbers = grep (/\d/, @array);    # Note: \d involves more digits than 0-9
map {print $_ . "\n" } @numbers;