Operators in the Perl language

One, arithmetic operators: + (plus),-(minus), * (multiply),/(except), * * (UP),% (remainder),-(Monocular negative)

(1) The base of the exponentiation can not be negative, such as ( -5) * * 2.5 # error;
(2) The result of a exponentiation cannot exceed the limit indicated by the computer, such as the 999999 # error
(3) The operand of the remainder, if not an integer, is rounded to an integer and the operator to the right cannot be zero
(4) Monocular negative can be used for variables:-$y; # equivalent to $y *-1
(5) corresponding to + =,-=, *=,/=, **=,%=

Second, integer comparison operators

Table 1. Integer comparison Operators

Operator	Describe
<	Less than
>	Greater than
==	Equals
<=	Less than or equal
>=	Greater than or equal
!=	Not equal to
<=>	Compare, return 1, 0,-1

The operators <=> results are:
0-Two values equal
1-Large first value
1-Large second value

Three, string comparison operators

Table 2. string comparison operators

Operator	Describe
Lt	Less than
Gt	Greater than
eq	Equals
Le	Less than or equal
Ge	Greater than or equal
Ne	Not equal to
Cmp	Compare, return 1, 0, or-1

Four, logical operators

Logic or: $a | | $b or $a or $b
Logic with: $a && $b or $a and $b
Logical non-:! $a or not $a
Logical XOR: $a XOR $b

Five, bitwise operators

Bits and:&
Bit or: |
Bit non: ~
Bit XOR: ^
Shift Left: $x << 1
Shift Right: $x >> 2
Note: Do not use & for negative integers, because Perl will convert them to unsigned numbers.

Six, assignment operators

Table 3. Assignment operators

Operator	Describe
=	Assignment only
+=	Addition and assignment
-=	Subtraction and assignment
*=	Multiplication and assignment
/=	Division and Assignment
%=	Remainder and assignment
**=	Exponentiation and Assignment
&=	Bitwise and and assignment
|=	Bitwise OR and Assignment
^=	Bitwise XOR and Assignment

Table 4. Assignment operator Examples

An expression	An equivalent expression
$a = 1;	None (Basic Assignment)
$a-= 1;	$a = $a-1;
$a *= 2;	$a = $a * 2;
$a/= 2;	$a = $a/2;
$a%= 2;	$a = $a% 2;
$a **= 2;	$a = $a * * 2;
$a &= 2;	$a = $a & 2;
$a |= 2;	$a = $a | 2;
$a ^= 2;	$a = $a ^ 2;

Note:
1. = can occur multiple times in an assignment statement, such as:
$value 1 = $value 2 = "a string";
2. = as a sub-expression
($a = $b) + = 3;
Equivalent to
$a = $b;