Operators in PHP

Who operates between two  operands are called as operators.

Example: a+b

Where a and b are two operands and + is the operator.

 Types

 PHP operators can be divided into following categories:

·         Arithmetic operators

·         Unary operators (Increment and decrement operator)

·         Relational operators or Comparison operators

·         Logical operators

·         Bitwise operators

·         Assignment operators

·         String operators

·         Array operators

 Arithmetic operators

Arithmetic operators are used in mathematical expression and algebra.

Operator	Description
+	adds two operands
-	subtract second operands from first
*	multiply two operand
/	Calculate quotient
%	remainder of division
++	Increment operator increases integer value by one
--	Decrement operator decreases integer value by one

       Unary operators (Increment and decrement operator)

Operator	Description
++	Incremented by 1
--	Decremented by 1

Relational or Comparison operators

Operator	Description
==	Check if two operands are equal
!=	Check if two operands are not equal.
>	Check if operand on the left is greater than operand on the right
<	Check operand on the left is smaller than right operand
>=	check left operand is greater than or equal to right operand
<=	Check if operand on left is smaller than or equal to right operand

Logical operators

Operator	Description
&&	Logical AND
||	Logical OR
!	Logical NOT

Bitwise operators

Operator	Description
&	Bitwise AND
|	Bitwise OR
^	Bitwise exclusive OR
>>	left shift
<<	right shift

truth table 

a	b	a & b	a | b	a ^ b
0	0	0	0	0
0	1	0	1	1
1	0	0	1	1
1	1	1	1	0

The bitwise shift operators shift the bit value. The left operand specifies the value to be shifted and the right operand specifies the number of positions that the bits in the value are to be shifted. Both operands have the same precedence.

Assignment Operators

Operator	Description	Example
=	assigns values from right side operands to left side operand	$a = $b
+=	adds right operand to the left operand and assign the result to left	$a+=$b is same as $a=$a+$b
-=	subtracts right operand from the left operand and assign the result to left operand	$a-=$b is same as $a=$a-$b
*=	multiply left operand with the right operand and assign the result to left operand	$a*=$b is same as$a=$a*$b
/=	divides left operand with the right operand and assign the result to left operand	$a/=$b is same as $a=$a/$b
%=	calculate modulus using two operands and assign the result to left operand	$a%=$b is same as $a=$a%$b

String Operators

Operator	Description	Example
.	Concatenation	$a .$b
.=	Concatenation assignment	$a .= $b

Array Operators

operator	Description	Example
+	Union	$a+ $b
==	Equality	$a == $b
===	Identity	$a === $b
!=	Inequality	$a != $b
<>	Inequality	$a <> $b
!==	Non-identity	$a!== $b