I wonder how the speed of

my $n = 534587;
print "even\n" if($n % 2 == 0);    # modulo operator of possibly a flo
+at or possibly an integer (*)
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compares with

use integer;
my $n = 534587;
print "even\n" if($n & 1 == 0);    # checking LSB with Bitwise And on 
+an integer
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(*) perlop: Integer-Arithmetic says
"By default, Perl assumes that it must do most of its arithmetic in floating point."

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Also I wonder how this

my $n = "534587";
print "even\n" if($n =~ /[02468]$/);    # reg exp
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compares with:

my $n = "534587";
my $c = substr($n, -1, 1);          # last char
print "even\n" if ( ($c == '0') || ($c == '2') || ($c == '4') || ($c =
+= '6') || ($c == '8') );    # no regexp
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