in reply to How to I check if a value is present in an array?
Why do you persist in using two arrays when virtually all the answers in your previous thread (A better way to make the script run faster?) advised you to use a hash, which would make your script at least an order of magnitude faster.
Anyway, you want something like:
grep($genes[$index] eq $_, @gl)
The first argument to grep is an expression or a block which is expected to return true or false.
package Cow { use Moo; has name => (is => 'lazy', default => sub { 'Mooington' }) } say Cow->new->name
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