#!/usr/bin/env perl

use v5.14;

my @array = (0, 1000..10_000, 'abcd');

for my $element (qw/a ab abc 100 1000 10000 abcd/) {
   say "With grep:";
   if (grep {/^$element$/} @array) {
      say "Element $element is there";
   } else {
      say "Element $element is not there";
   }
   
   say "With given-when:";
   given ($element) {
      when (\@array) {
         say "Element $element is there";
      }
      default {
         say "Element $element is not there";
      }
   }
   say "";
}