Perl Tutorial Perl References

Perl - Operators



Operators are used to perform operation on a single operand or two operands. Operators in Perl can be categorized as follows:

  • Arithmetic operators
  • Assignment operators
  • Comparison operators
  • Increment/Decrement operators
  • Logical operators
  • Bitwise operators
  • Quote-Like operators
  • Miscellaneous operators

Perl Arithmetic operators

Arithmetic operators are used to perform arithmetic operations on two operands.

OperatorNameDescription
+AdditionAdd two values
-SubtractionSubtract one value from another
*MultiplicationMultiply two values
/DivisionDivide one value by another
%ModuloReturns remainder of division operation
**Exponent / PowerReturns first operand raised to the power of second operand

Example

Perl Assignment operators

Assignment operators are used to assign values of right hand side expression to left hand side operand.

OperatorExpressionEquivalent toDescription
=a = 5a = 5Example
+=a += ba = a + b
-=a -= ba = a - b
*=a *= ba = a * b
/=a /= ba = a / b
%=a %= ba = a % b
**=a **= ba = a ** b
&=a &= ba = a & bMore Info
|=a |= b a = a | bMore Info
^=a ^= b a = a ^ bMore Info
>>=a >>= ba = a >> bMore Info
<<=a <<= ba = a << bMore Info

Perl Comparison operators

Comparison operators are used to compare values of two operands. It returns true when values matches and returns false when values does not match. Perl has two sets of comparison operators. One is used for comparing numerical values while other is used for comparing string values.

Numeric Comparison operators

Operator Description
==Equal: Checks the values of two operands and returns true if they are same.
!=Not equal: Checks the values of two operands and returns true if they are not same.
>Greater than: Checks the values of two operands and returns true if the value of first operand is greater than the value of second operand.
<Less than: Checks the values of two operands and returns true if the value of first operand is less than the value of second operand.
>=Greater than or equal to: Checks the values of two operands and returns true if the value of first operand is greater than or equal to the value of second operand.
<=Less than or equal to: Checks the values of two operands and returns true if the value of first operand is less than or equal to the value of second operand.
<=>Comparison Operator: Checks the values of two operands and returns values based on the values of two operands:
  • Returns -1 if the value of first operand is less than value of second operand.
  • Returns 0 if the values of two operands are equal.
  • Returns 1 if the value of first operand is greater than value of second operand.

Example


String Comparison operators

Operator Description
eqEqual: Checks the values of two operands and returns true if they are string-wise same.
neNot equal: Checks the values of two operands and returns true if they are string-wise not same.
gtGreater than: Checks the values of two operands and returns true if the first operand is string-wise greater than the second operand.
ltLess than: Checks the values of two operands and returns true if the first operand is string-wise less than the second operand.
geGreater than or equal to: Checks the values of two operands and returns true if the first operand is string-wise greater than or equal to the second operand.
leLess than or equal to: Checks the values of two operands and returns true if the first operand is string-wise less than or equal to the second operand.
cmpComparison Operator: Checks the values of two operands and returns values based on the values of two operands:
  • Returns -1 if the first operand is string-wise less than the second operand.
  • Returns 0 if the two operands are string-wise equal.
  • Returns 1 if the first operand is string-wise greater than the second operand.

Example

Perl Increment/Decrement operators

Increment and decrement operators are used to increase and decrease the value of variable.

OperatorNameDescriptionExample
++$xPre-incrementIncreases the value of $x by 1, then returns $x.Example
$x++Post-incrementReturns $x, then increases the value of $x by 1.
--$xPre-decrementDecreases the value of $x by 1, then returns $x.Example
$x--Post-decrementReturns $x, then decreases the value of $x by 1.

Perl Logical operators

Logical operators are used to combine two or more conditions.

Operator NameDescription
and Logical ANDReturns true when all conditions are true
&&
orLogical ORReturns true when any of the conditions is true
||
notLogical NOTReturns true when given conditions is not true
!

More Info

Perl Bitwise operators

Bitwise operators are used to perform bitwise operations on two operands.

OperatorNameDescriptionMore Info
&ANDReturns 1 if both bits at the same position in both operands are 1, else returns 0.More Info
|ORReturns 1 if one of two bits at the same position in both operands is 1, else returns 0.More Info
^XORReturns 1 if only one of two bits at the same position in both operands is 1, else returns 0.More Info
~NOTReverse all the bits.More Info
>>Right shiftThe left operand is moved right by the number of bits present in the right operand.More Info
<<Left shiftThe left operand value is moved left by the number of bits present in the right operand.More Info

Quote-Like operators

Perl supports the following Quote-like operators:

OperatorDescription
q{ }Encloses a string with-in single quotes.
qq{ }Encloses a interpolated string with-in double quotes.
qx{ }Encloses a (possibly) interpolated string and then executed as a system command, via /bin/sh or its equivalent if required.

Perl Miscellaneous operators

The table below describes other operators supported by Perl:

OperatorDescription
ternary operator (?:)Returns one of the two values based on value of boolean expression.

Perl Operators Precedence

Operator precedence (order of operations) is a collection of rules that reflect conventions about which procedures to perform first in order to evaluate a given expression.

For example, multiplication has higher precedence than addition. Thus, the expression 1 + 2 × 3 is interpreted to have the value 1 + (2 × 3) = 7, and not (1 + 2) × 3 = 9. When exponent is used in the expression, it has precedence over both addition and multiplication. Thus 3 + 52 = 28 and 3 × 52 = 75.

The following table lists the precedence and associativity of Perl operators. Operators are listed top to bottom, in descending precedence. Operators with higher precedence are evaluated before operators with relatively lower precedence. When operators have the same precedence, associativity of the operators determines the order in which the operations are performed.

PrecedenceOperatorDescriptionAssociativity
25terms and list operatorsterms and list operators (leftward)Left to Right
24->Arrow operator
23++a  --aPrefix increment, Prefix decrementnon-associative
a++  a--Postfix increment, Postfix decrement
22**Exponentiation operatorRight to Left
21!Logical NOT
~Bitwise NOT
~.Bitwise string NOT
\Reference operator
+a  -aUnary plus and minus
20=~  !~Pattern matching operatorsLeft to Right
19*  /  %Multiplication, Division, Remainder
xRepetition operator
18+  -  .Addition, Subtraction, Concatenating operator
17<<  >>Bitwise left shift and right shift
16Named unary operatorsNamed unary operatorsnon-associative
15isaClass instance Operator
14<  <=  >  >=Less than, Less than or equal, Greater than, and Greater than or equalchained
lt  le  gt  geString comparison operators: Less than, Less than or equal, Greater than, and Greater than or equalchained
13==  !=Equality and inequality operatorchain/na
eq  neString equality and inequality operator
<=>Two sided comparison operator
cmpString two sided comparison operator
~~Smartmatch operator
12&  &.Bitwise AND, Bitwise string ANDLeft to Right
11|  |.Bitwise OR, Bitwise string OR
^  ^.Bitwise XOR, Bitwise string XOR
10&&C-style Logical AND operator
9||C-style Logical OR operator
//Perl-style Logical OR operator
8..Range operatornon-associative
...yada-yada operator
7a?b:cternary (conditional) operatorRight to Left
6=Direct assignment
+=  -=  *=  /=  %=  **=Compound assignment by addition, subtraction, multiplication, division, remainder, and exponentiation
<<=  >>=Compound assignment by Bitwise left shift and right shift
&=  ^=  |=Compound assignment by Bitwise AND, XOR and OR
&.=  ^.=  |.=Compound assignment by Bitwise string AND, XOR and OR
gotogoto statement
lastlast statement
nextnext statement
redoredo statement
dumpdump statement
5,  =>Comma operatorsLeft to Right
4list operatorslist operators (rightward)non assoc
3notLogical NOTRight to Left
2andLogical ANDLeft to Right
1orLogical OR
xorBitwise XOR

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