PHP Operators
12 min read
In this tutorial you will learn how to manipulate or perform the operations on variables and values using operators in PHP.
1 - What is Operators in PHP
Operators are symbols that tell the PHP processor to perform certain actions. For example, the addition (+) symbol is an operator that tells PHP to add two variables or values, while the greater-than (>) symbol is an operator that tells PHP to compare two values.
The following lists describe the different operators used in PHP.
2 - PHP Arithmetic Operators
The arithmetic operators are used to perform common arithmetical operations, such as addition, subtraction, multiplication etc. Here's a complete list of PHP's arithmetic operators:
| Operator | Description | Example | Result |
|---|---|---|---|
+ | Addition | $x + $y | Sum of $x and $y |
- | Subtraction | $x - $y | Difference of $x and $y. |
* | Multiplication | $x * $y | Product of $x and $y. |
/ | Division | $x / $y | Quotient of $x and $y |
% | Modulus | $x % $y | Remainder of $x divided by $y |
The following example will show you these arithmetic operators in action.
Example:
<?php
$x = 10;
$y = 4;
echo($x + $y); // 0utputs: 14
echo($x - $y); // 0utputs: 6
echo($x * $y); // 0utputs: 40
echo($x / $y); // 0utputs: 2.5
echo($x % $y); // 0utputs: 2
?>2 - PHP Assignment Operators
The assignment operators are used to assign values to variables.
| Operator | Description | Example | Is The Same As |
|---|---|---|---|
= | Assign | $x = $y | $x = $y |
+= | Add and assign | $x += $y | $x = $x + $y |
-= | Subtract and assign | $x -= $y | $x = $x - $y |
*= | Multiply and assign | $x *= $y | $x = $x * $y |
/= | Divide and assign quotient | $x /= $y | $x = $x / $y |
%= | Divide and assign modulus | $x %= $y | $x = $x % $y |
Example:
The following example will show you these assignment operators in action:
<?php
$x = 10;
echo $x; // Outputs: 10
$x = 20;
$x += 30;
echo $x; // Outputs: 50
$x = 50;
$x -= 20;
echo $x; // Outputs: 30
$x = 5;
$x *= 25;
echo $x; // Outputs: 125
$x = 50;
$x /= 10;
echo $x; // Outputs: 5
$x = 100;
$x %= 15;
echo $x; // Outputs: 10
?>
3 - PHP Comparison Operators
The comparison operators are used to compare two values in a Boolean fashion.
| Operator | Name | Example | Result |
|---|---|---|---|
== | Equal | $x == $y | True if $x is equal to $y |
=== | Identical | $x === $y | True if $x is equal to $y, and they are of the same type |
!= | Not equal | $x != $y | True if $x is not equal to $y |
<> | Not equal | $x <> $y | True if $x is not equal to $y |
!== | Not identical | $x !== $y | True if $x is not equal to $y, or they are not of the same type |
< | Less than | $x < $y | True if $x is less than $y |
> | Greater than | $x > $y | True if $x is greater than $y |
>= | Greater than or equal to | $x >= $y | True if $x is greater than or equal to $y |
<= | Less than or equal to | $x <= $y | True if $x is less than or equal to $y |
Example:
The following example will show you these comparison operators in action:
<?php
$x = 25;
$y = 35;
$z = "25";
var_dump($x == $z); // Outputs: boolean true
var_dump($x === $z); // Outputs: boolean false
var_dump($x != $y); // Outputs: boolean true
var_dump($x !== $z); // Outputs: boolean true
var_dump($x < $y); // Outputs: boolean true
var_dump($x > $y); // Outputs: boolean false
var_dump($x <= $y); // Outputs: boolean true
var_dump($x >= $y); // Outputs: boolean false
?>4 - PHP Incrementing and Decrementing Operators
The increment/decrement operators are used to increment/decrement a variable's value.
| Operator | Name | Effect |
|---|---|---|
++$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:
The following example will show you these increment and decrement operators in action:
<?php
$x = 10;
echo ++$x; // Outputs: 11
echo $x; // Outputs: 11
$x = 10;
echo $x++; // Outputs: 10
echo $x; // Outputs: 11
$x = 10;
echo --$x; // Outputs: 9
echo $x; // Outputs: 9
$x = 10;
echo $x--; // Outputs: 10
echo $x; // Outputs: 9
?>5 - PHP Logical Operators
The logical operators are typically used to combine conditional statements.
| Operator | Name | Example | Result |
|---|---|---|---|
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:
The following example will show you these logical operators in action:
<?php
$year = 2014;
// Leap years are divisible by 400 or by 4 but not 100
if(($year % 400 == 0) || (($year % 100 != 0) && ($year % 4 == 0))){
echo "$year is a leap year.";
} else{
echo "$year is not a leap year.";
}
?>6 - PHP String Operators
There are two operators which are specifically designed for strings.
| Operator | Description | Example | Result |
|---|---|---|---|
. | Concatenation | $str1 . $str2 | Concatenation of $str1 and $str2 |
.= | Concatenation assignment | $str1 .= $str2 | Appends the $str2 to the $str1 |
Example:
The following example will show you these string operators in action:
<?php
$x = "Hello";
$y = " World!";
echo $x . $y; // Outputs: Hello World!
$x .= $y;
echo $x; // Outputs: Hello World!
?>7 - PHP Array Operators
The array operators are used to compare arrays:
| Operator | Name | Example | Result |
|---|---|---|---|
+ | Union | $x + $y | Union of $x and $y |
= | Equality | $x == $y | True if $x and $y have the same key/value pairs |
== | Identity | $x === $y | True if $x and $y have the same key/value pairs in the same order and of the same types |
!= | Inequality | $x != $y | True if $x is not equal to $y |
<> | Inequality | $x <> $y | True if $x is not equal to $y |
!== | Non-identity | $x !== $y | True if $x is not identical to $y |
Example:
The following example will show you these array operators in action:
<?php
$x = array("a" => "Red", "b" => "Green", "c" => "Blue");
$y = array("u" => "Yellow", "v" => "Orange", "w" => "Pink");
$z = $x + $y; // Union of $x and $y
var_dump($z);
var_dump($x == $y); // Outputs: boolean false
var_dump($x === $y); // Outputs: boolean false
var_dump($x != $y); // Outputs: boolean true
var_dump($x <> $y); // Outputs: boolean true
var_dump($x !== $y); // Outputs: boolean true
?>8 - PHP Spaceship Operator PHP 7
PHP 7 introduces a new spaceship operator (<=>) which can be used for comparing two expressions. It is also known as combined comparison operator.
The spaceship operator returns 0 if both operands are equal, 1 if the left is greater, and -1 if the right is greater. It basically provides three-way comparison as shown in the following table:
| Operator | <=> Equivalent |
|---|---|
$x < $y | ($x <=> $y) === -1 |
$x <= $y | ($x <=> $y) === -1 || ($x <=> $y) === 0 |
$x == $y | ($x <=> $y) === 0 |
$x != $y | ($x <=> $y) !== 0 |
$x >= $y | ($x <=> $y) === 1 || ($x <=> $y) === 0 |
$x > $y | ($x <=> $y) === 1 |
Example:
The following example will show you how spaceship operator actually works:
<?php
// Comparing Integers
echo 1 <=> 1; // Outputs: 0
echo 1 <=> 2; // Outputs: -1
echo 2 <=> 1; // Outputs: 1
// Comparing Floats
echo 1.5 <=> 1.5; // Outputs: 0
echo 1.5 <=> 2.5; // Outputs: -1
echo 2.5 <=> 1.5; // Outputs: 1
// Comparing Strings
echo "x" <=> "x"; // Outputs: 0
echo "x" <=> "y"; // Outputs: -1
echo "y" <=> "x"; // Outputs: 1
?>