Operators are used to perform operations on variables and values.
PHP divides the operators in the following groups:
- Arithmetic operators
- Assignment operators
- Comparison operators
- Increment/Decrement operators
- Logical operators
- String operators
- Array operators
PHP Arithmetic Operators
The PHP arithmetic operators are used with numeric values to perform common arithmetical operations, such as addition, subtraction, multiplication etc.
| Operator | Name | 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 |
| ** | Exponentiation | $x ** $y | Result of raising $x to the $y’th power (Introduced in PHP 5.6) |
Addition Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 10;
$y = 6;
echo $x + $y;
?>
</body>
</html>
Output
Subtraction Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 10;
$y = 6;
echo $x – $y;
?>
</body>
</html>
Output
Multiplication Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 10;
$y = 6;
echo $x * $y;
?>
</body>
</html>
Output
Division Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 10;
$y = 6;
echo $x / $y;
?>
</body>
</html>
Output
Modulus Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 10;
$y = 6;
echo $x % $y;
?>
</body>
</html>
Output
Exponentiation Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 2;
$y = 8;
echo $x ** $y;
?>
</body>
</html>
Output
PHP Assignment Operators
The PHP assignment operators are used with numeric values to write a value to a variable.
The basic assignment operator in PHP is “=”. It means that the left operand gets set to the value of the assignment expression on the right.
| Assignment | Same as… | Description |
| x = y | x = y | The left operand gets set to the value of the expression on the right |
| 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 |
Equality Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 10;
echo $x;
?>
</body>
</html>
Output
Addition Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 20;
$x += 100;
echo $x;
?>
</body>
</html>
Output
Subtraction Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 50;
$x -= 30;
echo $x;
?>
</body>
</html>
Output
Multiplication Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 10;
$x *= 10;
echo $x;
?>
</body>
</html>
Output
Division Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 10;
$x /= 5;
echo $x;
?>
</body>
</html>
Output
Modulus Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 15;
$x %= 4;
echo $x;
?>
</body>
</html>
Output
PHP Comparison Operators
The PHP comparison operators are used to compare two values (number or string):
| Operator | Name | Example | Result |
| == | Equal | $x == $y | Returns true if $x is equal to $y |
| === | Identical | $x === $y | Returns true if $x is equal to $y, and they are of the same type |
| != | Not equal | $x != $y | Returns true if $x is not equal to $y |
| <> | Not equal | $x <> $y | Returns true if $x is not equal to $y |
| !== | Not identical | $x !== $y | Returns true if $x is not equal to $y, or they are not of the same type |
| > | Greater than | $x > $y | Returns true if $x is greater than $y |
| < | Less than | $x < $y | Returns true if $x is less than $y |
| >= | Greater than or equal to | $x >= $y | Returns true if $x is greater than or equal to $y |
| <= | Less than or equal to | $x <= $y | Returns true if $x is less than or equal to $y |
Equal Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 100;
$y = “100”;
var_dump($x == $y); // returns true because values are equal
?>
</body>
</html>
Output
Identical Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 100;
$y = “100”;
var_dump($x === $y); // returns false because types are not equal
?>
</body>
</html>
Output
Not equal Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 100;
$y = “100”;
var_dump($x != $y); // returns false because values are equal
?>
</body>
</html>
Output
Not equal Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 100;
$y = “100”;
var_dump($x <> $y); // returns false because values are equal
?>
</body>
</html>
Output
Not identical Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 100;
$y = “100”;
var_dump($x !== $y); // returns true because types are not equal
?>
</body>
</html>
Output
Greater than Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 100;
$y = 50;
var_dump($x > $y); // returns true because $x is greater than $y
?>
</body>
</html>
Output
Less than Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 10;
$y = 50;
var_dump($x < $y); // returns true because $x is less than $y
?>
</body>
</html>
Output
Greater than or equal to Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 50;
$y = 50;
var_dump($x >= $y); // returns true because $x is greater than or equal to $y
?>
</body>
</html>
Output
Less than or equal to Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 50;
$y = 50;
var_dump($x <= $y); // returns true because $x is less than or equal to $y
?>
</body>
</html>
Output
PHP Increment / Decrement Operators
The PHP increment operators are used to increment a variable’s value.
The PHP decrement operators are used to decrement a variable’s value.
| Operator | Name | Description |
| ++$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 |
Pre-increment Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 10;
echo $x++;
?>
</body>
</html>
Output
Post-increment Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 10;
echo ++$x;
?>
</body>
</html>
Output
Pre-decrement Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 10;
echo –$x;
?>
</body>
</html>
Output
Post-decrement Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 10;
echo $x–;
?>
</body>
</html>
Output
PHP Logical Operators
The PHP logical operators are 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 |
And Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 100;
$y = 50;
if ($x == 100 and $y == 50) {
echo “Robert Karamagi”;
}
?>
</body>
</html>
Output
Or Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 100;
$y = 50;
if ($x == 100 or $y == 80) {
echo “Robert Karamagi”;
}
?>
</body>
</html>
Output
Xor Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 100;
$y = 50;
if ($x == 100 xor $y == 80) {
echo “Robert Karamagi”;
}
?>
</body>
</html>
Output
And Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 100;
$y = 50;
if ($x == 100 && $y == 50) {
echo “Robert Karamagi”;
}
?>
</body>
</html>
Output
Or Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 100;
$y = 50;
if ($x == 100 || $y == 80) {
echo “Robert Karamagi”;
}
?>
</body>
</html>
Output
Not Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = 100;
if ($x !== 90) {
echo “Robert Karamagi”;
}
?>
</body>
</html>
Output
PHP String Operators
PHP has two operators that are specially designed for strings.
| Operator | Name | Example | Result |
| . | Concatenation | $txt1 . $txt2 | Concatenation of $txt1 and $txt2 |
| .= | Concatenation assignment | $txt1 .= $txt2 | Appends $txt2 to $txt1 |
Concatenation Example
<!DOCTYPE html>
<html>
<body>
<?php
$txt1 = “Robert”;
$txt2 = ” Karamagia”;
echo $txt1 . $txt2;
?>
</body>
</html>
Output
Concatenation assignment Example
<!DOCTYPE html>
<html>
<body>
<?php
$txt1 = “Robert”;
$txt2 = ” Karamagi”;
$txt1 .= $txt2;
echo $txt1;
?>
</body>
</html>
Output
PHP Array Operators
The PHP array operators are used to compare arrays.
| Operator | Name | Example | Result |
| + | 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 |
Union Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = array(“a” => “red”, “b” => “green”);
$y = array(“c” => “blue”, “d” => “yellow”);
print_r($x + $y); // union of $x and $y
?>
</body>
</html>
Output
Equality Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = array(“a” => “red”, “b” => “green”);
$y = array(“b” => “green”, “a” => “red”);
var_dump($x == $y);
?>
</body>
</html>
Output
Identity Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = array(“a” => “red”, “b” => “green”);
$y = array(“b” => “green”, “a” => “red”);
var_dump($x === $y);
?>
</body>
</html>
Output
Inequality Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = array(“a” => “red”, “b” => “green”);
$y = array(“c” => “blue”, “d” => “yellow”);
var_dump($x != $y);
?>
</body>
</html>
Output
Inequality Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = array(“a” => “red”, “b” => “green”);
$y = array(“c” => “red”, “d” => “green”);
var_dump($x <> $y);
?>
</body>
</html>
Output
Non-identity Example
<!DOCTYPE html>
<html>
<body>
<?php
$x = array(“a” => “red”, “b” => “green”);
$y = array(“a” => “red”, “b” => “green”);
var_dump($x !== $y);
?>
</body>
</html>
Output
Robert Karamagi 