a little syntactic sugar with an improvised in operator and given/when has no better readability anymore.¹

use strict;
use warnings;

sub in {
    for my $val (@_) {
        return 1 if  $_ eq $val;
    }
    return;
}

sub test1 {
    my ($var) = @_;
    my $i;
    for ($var) {
        if    ( in 1 )     { $i = "One" }
        elsif ( in 2 )     { $i = "Two" }
        elsif ( in 3,4,5 ) { $i = "Three, Four or Five" }
        else               { $i = "Other" }
    }
    print "$var is $i\n";
}

sub test2 {
    my ($var) = @_;
    my $i;
    for ($var) {
        if    ( in 1 )     { $i = "One" ;next}
        if    ( in 2 )     { $i = "Two" ;next}
        if    ( in 3,4,5 ) { $i = "Three, Four or Five" ;next}
        $i = "Other" 
    }
    print "$var is $i\n";
}


test1($_) for 1..6;
test2($_) for 1..6;
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¹) though I think it's still faster, it might be able to automatically optimize to hash-lookups