Operators in PHP are used to perform different operations on operands. Operators can be categorized in following types :
- Arithmetic operators
- Assignment operators
- Comparison operators
- Increment/Decrement operators
- Logical operators
- String operators
- Array operators
Arithmetic operators : Arithmetic operators are used with numeric values to perform common arithmetical operations, such as addition, subtraction, multiplication etc. Assume variable $x holds 20 and variable $y holds 10, then :
Operators | Name | Description | Example |
---|---|---|---|
+ | Addition | Sum of $x and $y | $x + $y =30 |
- | Subtraction | Difference of $x and $y | $x - $y = -10 |
* | Multiplication | Products of $x and $y | $x * $y = 200 |
/ | Division | Quotient of $x and $y | $x / $y = 2 |
% | Modulus | Remiander of $x divided by $y | $x % $y = 0 |
** | Exponentiation | Result of raising $x to the $y'th power | $x ** $y = 10240000000000 |
Example :
Output :
<?php
$a = 12;
$b = 8;
$c = $a + $b;
echo $c;
?>
$a = 12;
$b = 8;
$c = $a + $b;
echo $c;
?>
Output :
20
Assignment operators : Assignment operators are used with numeric values to write a value to a variable.
Shorthand | Expression | Description |
---|---|---|
$x += $y | $x = $x + $y | Addition |
$x -= $y | $x = $x - $y | Subtraction |
$x *= $y | $x = $x * $y | Multiplication |
$x /= $y | $x = $x / $y | Division |
$x %= $y | $x = $x % $y | Modulus |
Example :
<?php
$x = 10;
$y = 5;
$x += $y;
echo $x."<br>";
$x -= $y;
echo $x."<br>";
$x *= $y;
echo $x."<br>";
$x /= $y;
echo $x."<br>";
$x %= $y;
echo $x;
?>
$x = 10;
$y = 5;
$x += $y;
echo $x."<br>";
$x -= $y;
echo $x."<br>";
$x *= $y;
echo $x."<br>";
$x /= $y;
echo $x."<br>";
$x %= $y;
echo $x;
?>
Output :
15
10
50
10
0
10
50
10
0
Comparison operators : Comparison operators are used in PHP to compare two values (number or string). Assume variable $x holds 20 and variable $y holds 10, then :
Operators | Name | Description | Example |
---|---|---|---|
== | Equal | Returns true if $x is equal to $y | ($x == $y) is false |
=== | Identical | Returns true if $x is equal to $y, and they are of the same type | ($x === $y) is false |
!= | Not equal | Returns true if $x is not equal to $y | ($x != $y) is true |
<> | Not equal | Returns true if $x is not equal to $y | ($x <> $y) is true |
!== | Not identical | Returns true if $x is not equal to $y, or they are not of the same type | ($x !== $y) is true |
> | Greater than | Returns true if $x is greater than $y | ($x > $y) is true |
< | Less than | Returns true if $x is less than $y | ($x < $y) is false |
>= | Greater than or equal to | Returns true if $x is greater than or equal to $y | ($x >= $y) is true |
<= | Less than or equal to | Returns true if $x is less than or equal to $y | ($x < $y) is false |
Increment/Decrement operators : In PHP increment operators are used to increment a variable's value and decrement operators are used to decrement a variable's value.
Operator | Name | Description |
---|---|---|
++$x | Pre-increment | Increments $x by one, then returns $x |
$x++ | Post-increment | Returns $x, then increments $x by one |
--$x | Pre-decrement | Decrements $x by one, then returns $x |
$x-- | Post-decrement | Returns $x, then decrements $x by one |
Example :
<?php
$x = 10;
echo ++$x."<br>";
$y = 20;
echo $y++."<br>";
$a = 15;
echo --$a."<br>";
$b = 25;
echo $b--;
?>
$x = 10;
echo ++$x."<br>";
$y = 20;
echo $y++."<br>";
$a = 15;
echo --$a."<br>";
$b = 25;
echo $b--;
?>
Output :
11
20
14
25
20
14
25
Logical operators : Logical operators are used to combine conditional statements.
Operators | Name | Expression | Description |
---|---|---|---|
and | And | $x and $y | True if both $x and $y are true |
or | Or | $x or $y | True if either $x or $y is true |
xor | Xor | $x xor $y | True if either $x or $y is true, but not both |
&& | And | $x && $y | True if both $x and $y are true |
|| | Or | $x || $y | True if either $x or $y is true |
! | Not | !$x | True if $x is not true |
Example :
<?php
$x = 10;
$y=20;
if($x==10 and $y==20)
{
echo "True"."<br>";
}
if($x==10 or $y==30)
{
echo "True"."<br>";
}
if($x==10 and $y==20)
{
echo "False"."<br>";
}
if($x !==20)
{
echo "True"."<br>";
}
?>
$x = 10;
$y=20;
if($x==10 and $y==20)
{
echo "True"."<br>";
}
if($x==10 or $y==30)
{
echo "True"."<br>";
}
if($x==10 and $y==20)
{
echo "False"."<br>";
}
if($x !==20)
{
echo "True"."<br>";
}
?>
Output :
True
True
False
True
True
False
True
String operators :
Operator | Name | Expression | Description |
---|---|---|---|
. | Concatenation | $txt_1 . $txt_2 | Concatenation of $txt1 and $txt2 |
.= | Concatenation assignment | $txt_1 .= $txt_2 | Appends $txt_2 to $txt_1 |
Example :
<?php
$txt_1 = "Hello";
$txt_2 = " world";
echo $txt_1 . $txt_2."<br>";
$txt_3 = "My";
$txt_4= " PHP";
$txt_3 .= $txt_4;
echo $txt_3;
?>
$txt_1 = "Hello";
$txt_2 = " world";
echo $txt_1 . $txt_2."<br>";
$txt_3 = "My";
$txt_4= " PHP";
$txt_3 .= $txt_4;
echo $txt_3;
?>
Output :
Hello world
My PHP
My PHP
Array operators : Array operators are used in PHP to compare arrays.
Operator | Name | Expression | Description |
---|---|---|---|
+ | Union | $x + $y | Union of $x and $y |
== | Equality | $x == $y | Returns true if $x and $y have the same key/value pairs |
=== | Identity | $x === $y | Returns true if $x and $y have the same key/value pairs in the same order and of the same types |
!= | Inequality | $x != $y | Returns true if $x is not equal to $y |
<> | Inequality | $x <> $y | Returns true if $x is not equal to $y |
!== | Non-identity | $x !== $y | Returns true if $x is not identical to $y |
Example :
<?php
$x = array("a" => "red", "b" => "green");
$y = array("c" => "blue", "d" => "yellow");
print_r($x + $y);
?>
$x = array("a" => "red", "b" => "green");
$y = array("c" => "blue", "d" => "yellow");
print_r($x + $y);
?>
Output :
Array
(
[a] => red
[b] => green
[c] => blue
[d] => yellow
)
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