PHP Operators
PHP Operator is a symbol
i.e used to perform operations on operands. In simple words, operators are used
to perform operations on variables or values. For example:
$num=10+20;//+ is the operator and 10,20 are operands
In the above example, + is
the binary + operator, 10 and 20 are operands and $num is variable.
PHP Operators can be
categorized in following forms:
- Arithmetic Operators
- Assignment Operators
- Bitwise Operators
- Comparison Operators
- Incrementing/Decrementing Operators
- Logical Operators
- String Operators
- Array Operators
- Type Operators
- Execution Operators
- Error Control Operators
We
can also categorize operators on behalf of operands. They can be categorized in
3 forms:
- Unary Operators: works on single operands
such as ++, -- etc.
- Binary Operators: works on two operands
such as binary +, -, *, / etc.
- Ternary Operators: works on three operands
such as "?:".
Arithmetic Operators
The PHP arithmetic operators are used
to perform common arithmetic operations such as addition, subtraction, etc.
with numeric values.
|
Operator |
Name |
Example |
Explanation |
|
+ |
Addition |
$a
+ $b |
Sum
of operands |
|
- |
Subtraction |
$a
- $b |
Difference
of operands |
|
* |
Multiplication |
$a
* $b |
Product
of operands |
|
/ |
Division |
$a
/ $b |
Quotient
of operands |
|
% |
Modulus |
$a
% $b |
Remainder
of operands |
|
** |
Exponentiation |
$a
** $b |
$a
raised to the power $b |
The exponentiation (**)
operator has been introduced in PHP 5.6.
Assignment Operators
The assignment operators are used to
assign value to different variables. The basic assignment operator is
"=".
|
Operator |
Name |
Example |
Explanation |
|
= |
Assign |
$a = $b |
The value of right operand is assigned to
the left operand. |
|
+= |
Add then Assign |
$a += $b |
Addition same as $a = $a + $b |
|
-= |
Subtract then Assign |
$a -= $b |
Subtraction same as $a = $a - $b |
|
*= |
Multiply then Assign |
$a *= $b |
Multiplication same as $a = $a * $b |
|
/= |
Divide then Assign |
$a /= $b |
Find quotient same as $a = $a / $b |
|
%= |
Divide then Assign |
$a %= $b |
Find remainder same as $a = $a % $b |
Bitwise Operators
The bitwise operators are used to perform
bit-level operations on operands. These operators allow the evaluation and
manipulation of specific bits within the integer.
|
Operator |
Name |
Example |
Explanation |
|
& |
And |
$a & $b |
Bits that are 1 in both $a and $b are set
to 1, otherwise 0. |
|
| |
Or (Inclusive or) |
$a | $b |
Bits that are 1 in either $a or $b are set
to 1 |
|
^ |
Xor (Exclusive or) |
$a ^ $b |
Bits that are 1 in either $a or $b are set
to 0. |
|
~ |
Not |
~$a |
Bits that are 1 set to 0 and bits that are
0 are set to 1 |
|
<< |
Shift left |
$a << $b |
Left shift the bits of operand $a $b steps |
|
>> |
Shift right |
$a >> $b |
Right shift the bits of $a operand by $b
number of places |
Comparison Operators
Comparison operators allow comparing
two values, such as number or string. Below the list of comparison operators
are given:
|
Operator |
Name |
Example |
Explanation |
|
== |
Equal |
$a == $b |
Return TRUE if $a is equal to $b |
|
=== |
Identical |
$a === $b |
Return TRUE if $a is equal to $b, and they
are of same data type |
|
!== |
Not identical |
$a !== $b |
Return TRUE if $a is not equal to $b, and
they are not of same data type |
|
!= |
Not equal |
$a != $b |
Return TRUE if $a is not equal to $b |
|
<> |
Not equal |
$a <> $b |
Return TRUE if $a is not equal to $b |
|
< |
Less than |
$a < $b |
Return TRUE if $a is less than $b |
|
> |
Greater than |
$a > $b |
Return TRUE if $a is greater than $b |
|
<= |
Less than or equal to |
$a <= $b |
Return TRUE if $a is less than or equal $b |
|
>= |
Greater than or equal to |
$a >= $b |
Return TRUE if $a is greater than or equal
$b |
|
<=> |
Spaceship |
$a <=>$b |
Return -1 if $a is less than $b |
Incrementing/Decrementing
Operators
The increment and decrement
operators are used to increase and decrease the value of a variable.
|
Operator |
Name |
Example |
Explanation |
|
++ |
Increment |
++$a |
Increment the value of $a by one, then
return $a |
|
$a++ |
Return $a, then increment the value of $a
by one |
||
|
-- |
decrement |
--$a |
Decrement the value of $a by one, then
return $a |
|
$a-- |
Return $a, then decrement the value of $a
by one |
Logical Operators
The logical
operators are used to perform bit-level operations on operands. These operators
allow the evaluation and manipulation of specific bits within the integer.
|
Operator |
Name |
Example |
Explanation |
|
and |
And |
$a and $b |
Return TRUE if both $a and $b are true |
|
Or |
Or |
$a or $b |
Return TRUE if either $a or $b is true |
|
xor |
Xor |
$a xor $b |
Return TRUE if either $ or $b is true but
not both |
|
! |
Not |
! $a |
Return TRUE if $a is not true |
|
&& |
And |
$a && $b |
Return TRUE if either $a and $b are true |
|
|| |
Or |
$a || $b |
Return TRUE if either $a or $b is true |
String Operators
The string
operators are used to perform the operation on strings. There are two string
operators in PHP, which are given below:
|
Operator |
Name |
Example |
Explanation |
|
. |
Concatenation |
$a . $b |
Concatenate both $a and $b |
|
.= |
Concatenation and Assignment |
$a .= $b |
First concatenate $a and $b, then assign
the concatenated string to $a, e.g. $a = $a . $b |
Array Operators
The array
operators are used in case of array. Basically, these operators are used to
compare the values of arrays.
|
Operator |
Name |
Example |
Explanation |
|
+ |
Union |
$a + $y |
Union of $a and $b |
|
== |
Equality |
$a == $b |
Return TRUE if $a and $b have same
key/value pair |
|
!= |
Inequality |
$a != $b |
Return TRUE if $a is not equal to $b |
|
=== |
Identity |
$a === $b |
Return TRUE if $a and $b have same
key/value pair of same type in same order |
|
!== |
Non-Identity |
$a !== $b |
Return TRUE if $a is not identical to $b |
|
<> |
Inequality |
$a <> $b |
Return TRUE if $a is not equal to $b |
Type Operators
The type
operator instanceof is used to determine whether an
object, its parent and its derived class are the same type or not. Basically,
this operator determines which certain class the object belongs to. It is used
in object-oriented programming.
<?php
//class declaration
class Developer
{}
class Programmer
{}
//creating an object of type Developer
$charu = new Developer();
//testing the type of object
if( $charu instanceof Developer)
{
echo "Charu is a developer.";
}
else
{
echo "Charu is a programmer.";
}
echo "</br>";
var_dump($charu instanceof Developer); //It will return true.
var_dump($charu instanceof Programmer); //It will return false.
?>
Output:
Charu is a developer.bool(true) bool(false)
Execution Operators
PHP has an execution
operator backticks (``). PHP executes the content of
backticks as a shell command. Execution operator and shell_exec() give
the same result.
|
Operator |
Name |
Example |
Explanation |
|
`` |
backticks |
echo `dir`; |
Execute the shell command and return the result. |
Note: Note that backticks
(``) are not single-quotes.
Error Control Operators
PHP has one error control
operator, i.e., at (@) symbol. Whenever it is used with
an expression, any error message will be ignored that might be generated by
that expression.
|
Operator |
Name |
Example |
Explanation |
|
@ |
at |
@file ('non_existent_file') |
Intentional file error |
PHP Operators Precedence
Let's see the precedence of PHP operators
with associativity.
|
Operators |
Additional
Information |
Associativity |
|
clone new |
clone and new |
non-associative |
|
[ |
array() |
left |
|
** |
arithmetic |
right |
|
++ -- ~ (int) (float) (string) (array)
(object) (bool) @ |
increment/decrement and types |
right |
|
instanceof |
types |
non-associative |
|
! |
logical (negation) |
right |
|
* / % |
arithmetic |
left |
|
+ - . |
arithmetic and string concatenation |
left |
|
<< >> |
bitwise (shift) |
left |
|
< <= > >= |
comparison |
non-associative |
|
== != === !== <> |
comparison |
non-associative |
|
& |
bitwise AND |
left |
|
^ |
bitwise XOR |
left |
|
| |
bitwise OR |
left |
|
&& |
logical AND |
left |
|
|| |
logical OR |
left |
|
?: |
ternary |
left |
|
= += -= *= **= /= .= %= &= |= ^=
<<= >>= => |
assignment |
right |
|
and |
logical |
left |
|
xor |
logical |
left |
|
or |
logical |
left |
|
, |
many uses (comma) |
left |
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