Table of Contents
- Introduction to PHP Operators
- Types of PHP Operators
- Arithmetic Operators
- Assignment Operators
- Comparison Operators
- Increment/Decrement Operators
- Logical Operators
- String Operators
- Array Operators
- Spaceship and Null Coalescing Operators (PHP 7+)
- Operator Precedence in PHP
- Practical Examples
- Summary
Introduction to PHP Operators
In PHP, operators are symbols or combinations of symbols that perform operations on variables and values. Whether you’re adding numbers, comparing values, or evaluating logic conditions, operators are essential building blocks in any PHP program.
Understanding how each type of operator works will help you write clean, efficient, and bug-free code.
Types of PHP Operators
Let’s break down each category of operators in PHP.
1. Arithmetic Operators
Used to perform mathematical operations.
| Operator | Description | Example |
|---|---|---|
+ | Addition | $x + $y |
- | Subtraction | $x - $y |
* | Multiplication | $x * $y |
/ | Division | $x / $y |
% | Modulus (remainder) | $x % $y |
** | Exponentiation (PHP 5.6+) | $x ** $y |
Example:
$x = 10;
$y = 3;
echo $x % $y; // Output: 1
2. Assignment Operators
Used to assign values to variables.
| Operator | Example | Equivalent To |
|---|---|---|
= | $x = 5 | $x = 5 |
+= | $x += 3 | $x = $x + 3 |
-= | $x -= 2 | $x = $x - 2 |
*= | $x *= 4 | $x = $x * 4 |
/= | $x /= 2 | $x = $x / 2 |
%= | $x %= 3 | $x = $x % 3 |
3. Comparison Operators
Used to compare values; results in a boolean (true or false).
| Operator | Description | Example |
|---|---|---|
== | Equal (type-agnostic) | $x == $y |
=== | Identical (type-safe) | $x === $y |
!= | Not equal | $x != $y |
<> | Not equal (alt syntax) | $x <> $y |
!== | Not identical | $x !== $y |
> | Greater than | $x > $y |
< | Less than | $x < $y |
>= | Greater than or equal | $x >= $y |
<= | Less than or equal | $x <= $y |
4. Increment/Decrement Operators
These operators increase or decrease the value of a variable.
| Operator | Description | Example |
|---|---|---|
++$x | Pre-increment | Increment, then return value |
$x++ | Post-increment | Return value, then increment |
--$x | Pre-decrement | Decrement, then return value |
$x-- | Post-decrement | Return value, then decrement |
5. Logical Operators
Used to combine conditional statements.
| Operator | Description | Example |
|---|---|---|
and | Logical AND | $x and $y |
or | Logical OR | $x or $y |
xor | Logical XOR | $x xor $y |
&& | Logical AND | $x && $y |
| ` | ` | |
! | Logical NOT | !$x |
6. String Operators
Only two operators are used with strings in PHP.
| Operator | Description | Example |
|---|---|---|
. | Concatenation | $text = "Hello" . " World" |
.= | Concatenation & assign | $text .= "!" |
7. Array Operators
Used to compare or combine arrays.
| Operator | Description | Example |
|---|---|---|
+ | Union | $a + $b |
== | Equal | $a == $b |
=== | Identical | $a === $b |
!= | Not equal | $a != $b |
!== | Not identical | $a !== $b |
8. Special Operators (PHP 7+)
Spaceship Operator (<=>)
Returns -1, 0, or 1 when comparing two expressions.
echo 5 <=> 10; // Output: -1
Null Coalescing Operator (??)
Returns the first value if it exists and is not null.
$name = $_GET['name'] ?? 'Guest';
Operator Precedence in PHP
When multiple operators are used, precedence determines the execution order.
For example:
$result = 10 + 5 * 2; // Outputs 20 (5*2 first, then +10)
Use parentheses to override default precedence:
$result = (10 + 5) * 2; // Outputs 30
Practical Examples
$a = 10;
$b = 5;
$c = 15;
if ($a > $b && $c > $a) {
echo "Both conditions are true";
}
$text = "Hello";
$text .= " World";
echo $text; // Outputs "Hello World"
Summary
In this module, you explored all major operators in PHP—from arithmetic and logical to advanced ones like null coalescing and spaceship operators. Operators form the logical and mathematical backbone of any PHP application.
