Boolean Algebra

Exactly the way numbers can be combined with addition and multiplication, Boolean expressions can be combined with Logical Operators^3.1:

Example	Name	Result
$a && $b	And	$a if $a is false, $b otherwise
$a || $b	Or	$a if $a is true, $b otherwise
! $a	Not	True if $a is not true
$a and $b	And	$a if $a is false, $b otherwise
$a or $b	Or	$a if $a is true, $b otherwise
not $a	Not	True if $a is not true
$a xor $b	Xor	True if $a or $b is true, but not both

With 0 for false and 1 for true, binary addition is almost the same as boolean or. Binary multiplication is almost the same as boolean and. They function exactly the same because binary 10 (decimal 2) is true in perl. Thus, (1 and 1) is true in perl and (1+1) is true in perl.

+	0	1			*	0	1
0	0	1			0	0	0
1	1	10			1	0	1
||, or	0	1			&&, and	0	1
0	0	1			0	0	0
1	1	1			1	0	1

The value of the boolean expression can be saved in a variable.

$boolean = (2+4) eq 6;

print "$boolean\n";

will print

1

which from the definition of true and false 3.2.1 is true.