test2(1.00.000);

##</code><code>##

test2("1.00.000");

##</code><code>##

sub test2 {
    my ($var2) = @_;
    return ("One")    if ($var2 =~ /^1/ );
    return ("Two")    if ($var2 == /^2/ );
    return ("Three")  if ($var2 == /^3/ );
    return undef;
}

##</code><code>##

sub test2 {
    my ($var2) = @_;
    return ("One")    if ($var2 =~ /^1/ );
    return ("Two")    if ($var2 =~ /^2/ );
    return ("Three")  if ($var2 =~ /^3/ );
    return undef;
}

##</code><code>##

sub test2 {
    my $var2 = substr shift, 0, 1;
    return ("One")    if $var2 == 1 ;
    return ("Two")    if $var2 == 2 ;
    return ("Three")  if $var2 == 3 ;
    return undef;
}

##</code><code>##

use strict;
use warnings;
my @translation = qw / Zero One Two Three/;

sub test2 {
    return $translation[(substr shift, 0, 1)];
}
print test2("1.00.000");

##</code><code>##

use strict;
use warnings;
use Benchmark  qw/cmpthese/;
my @translation = qw / Zero One Two Three/;

sub test1 {
    my $var2 = shift;
    return ("One")    if ($var2 =~ /^1/ );
    return ("Two")    if ($var2 =~ /^2/ );
    return ("Three")  if ($var2 =~ /^3/ );
    return undef;
}
sub test2 {
    my $var2 = substr shift, 0, 1;
    return ("One")    if ($var2 == 1 );
    return ("Two")    if ($var2 == 2 );
    return ("Three")  if ($var2 == 3 );
    return undef;
}
sub test3 {
    return $translation[(substr shift, 0, 1)];
}
cmpthese( -1,
	{
	test_1 => sub {test1("3.01.000")},
	test_2 => sub {test2("3.01.000")},
	test_3 => sub {test3("3.01.000")},
	}
)

##</code><code>##

$ perl test_if.pl
            Rate test_1 test_2 test_3
test_1 1294050/s     --   -11%   -51%
test_2 1451608/s    12%     --   -45%
test_3 2642856/s   104%    82%     --