#!/usr/bin/perl
use strict;
use warnings;
use Benchmark qw( timethese cmpthese ) ;

my @numbers = qw(1 -1 123.1 0.1 Characters);

my $swithRefLoop = 'foreach my $number (@numbers) {
    checkInputStringWithSwitchConditions($number);
}';

my $ifAndElsIfRefLoop = 'foreach my $number (@numbers) {
    checkInputStringWithIfAndElseConditions($number);
}';

my $Benchmark = timethese( -10, {
    IfAndElsIfLoop => $ifAndElsIfRefLoop,
    SwitchLoop => $swithRefLoop,
			   } );
cmpthese $Benchmark;

sub checkInputStringWithSwitchConditions {
    use Switch;
    switch ($_[0]) {
	case /^[+-]?\d+\z/		                 { print "The $_[0] is a +/- integer\n" }
	case /^[+-]?(?=\.?\d)\d*\.?\d*(?:e[+-]?\d+)?\z/i { print "The $_[0] is a C float\n" }
	case /\D/                                        { print "The $_[0] has nondigits\n" }
	else		                                 { print "Non of the cases where True\n" }
    }
}

sub checkInputStringWithIfAndElseConditions {
    if ( $_[0] =~ /^[+-]?\d+\z/ ) {
	print "The $_[0] is a +/- integer\n";
    }
    elsif ( $_[0] =~ /^[+-]?(?=\.?\d)\d*\.?\d*(?:e[+-]?\d+)?\z/i ) {
	print "The $_[0] is a C float\n";
    }
    elsif ( $_[0] =~ /\D/ ) {
	print "The $_[0] has nondigits\n";
    }
}

__END__

Benchmark: running IfAndElsIfLoop, SwitchLoop for at least 10 CPU seconds...
IfAndElsIfLoop: 11 wallclock secs (10.04 usr + -0.00 sys = 10.04 CPU) @ 4954765.54/s (n=49745846)
SwitchLoop:  9 wallclock secs (10.04 usr +  0.00 sys = 10.04 CPU) @ 5691789.84/s (n=57145570)
                    Rate IfAndElsIfLoop     SwitchLoop
IfAndElsIfLoop 4954766/s             --           -13%
SwitchLoop     5691790/s            15%             --