I don't think that given()when() is any big deal.
The "old" Perl ways are more than adequate to do this. 
use strict;
use warnings;

sub test1  #An if/else implementation....
{
    my ($var1) = @_;
    # $var1 = shift;          # is slightly faster with one var
    # my ($var1, $var2) = @_; # slightly faster than than 2 shifts  
    # normally this minor difference doesn't matter. 
   
    # Perl can implement the if/else idea very code efficiently.
    
    return ("One")    if ($var1 == 1);
    return ("Two")    if ($var1 == 2);
    return ("Three")  if ($var1 == 3);
    return undef;
}

#Using a hash table
#Perl will not re-evaluate %hash for every entry into the sub
#that table will "still be around to use".

sub test2
{
   my $in = shift;
   my %hash = ( 1 => "One",
                2 => "Two",
                3 => "Three",
               );
   return ($hash{$in}) if exists ($hash{$in});
   return undef;
}

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In reply to Re: Given When Syntax by Marshall
in thread Given When Syntax by Deep_Plaid

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