PHP Operators
An operator is a character that represents an action.
Examples:
- + is an arithmetic operator which represents addition.
- - is an arithmetic operator which represents subtraction.
PHP has 11 types of operators.
- Arithmetic Operators
- Assignment Operators
- Comparison Operators
- Logical Operators
- Incrementing/Decrementing Operators
- String Operators
- Array Operators
- Type Operators
- Bitwise Operators
- Error Control Operators
- Execution Operators
Also, we have a new useful operator added in PHP 7.
Note: In this tutorial, we will only learn about the first 7 types of operators, as they are the ones that used most commonly.
PHP Arithmetic Operators
This is almost the same as the basic arithmetic operators you learned in your school.
| Operator | Name | Example | Result | |
|---|---|---|---|---|
| + | Addition | $a + $b | Sum of $a and $b | Run Example ›› |
| - | Subtraction | $a - $b | Difference of $a and $b | Run Example ›› |
| * | Multiplication | $a * $b | Product of $a and $b | Run Example ›› |
| / | Division | $a / $b | Quotient of $a and $b | Run Example ›› |
| % | Modulus | $a % $b | Remainder of $a / $b | Run Example ›› |
| ** | Exponentiation | $a ** $b | Result of raising $a to the $b'th power | Run Example ›› |
PHP Assignments Operators
The basic assignment operator in PHP is =. It is actually not the "equal" mark in PHP. It works as assignment operator, which assigns a value to a variable.
PHP Basic Assignment Operator Example
<?php
$a = 5;
$b = 7;
$a = $b;
echo $a; // outputs 7
In this example,
- 5 is assigned to $a.
- 7 is assigned to $b.
- Then, the value of $b (7) is assigned to $a.
There are some other assignment operators to learn.
| Operator | Example | Long Form | Description | |
|---|---|---|---|---|
| = | $a = $b | $a = $b | $a gets set to the value of $b | Run Example ›› |
| += | $a += $b | $a = $a + $b | $a gets set to $a + $b (Addition) | Run Example ›› |
| -= | $a -= $b | $a = $a - $b | $a gets set to $a - $b (Subtraction) | Run Example ›› |
| *= | $a *= $b | $a = $a * $b | $a gets set to $a * $b (Multiplication) | Run Example ›› |
| /= | $a /= $b | $a = $a / $b | $a gets set to $a / $b (Division) | Run Example ›› |
| %= | $a %= $b | $a = $a % $b | $a gets set to $a % $b (Modulus) | Run Example ›› |
| **= | $a **= $b | $a = $a ** $b | $a gets set to $a ** $b (Exponentiation) | Run Example ›› |
PHP Comparison Operators
Comparison Operators allow you to compare two values.
| Operator | Name | Example | Result | |
|---|---|---|---|---|
| == | Equal | $a == $b | True if values of $a and $b are equal | Run Example ›› |
| === | Identical | $a === $b | True if both values and data types of $a and $b are equal | Run Example ›› |
| != | Not equal | $a != $b | True if $a is not equal to $b | Run Example ›› |
| <> | Not equal | $a <> $b | True if $a is not equal to $b | Run Example ›› |
| !== | Not identical | $a !== $b | True if $a is not equal to $b or they are not in the same data type | Run Example ›› |
| > | Greater than | $a > $b | True if $a is greater than $b | Run Example ›› |
| < | Less than | $a < $b | True if $a is less than $b | Run Example ›› |
| >= | Greater than or equal to | $a >= $b | True if $a is greater than or equal to $b | Run Example ›› |
| <= | Less than or equal to | $a <= $b | True if $a is less than or equal to $b | Run Example ›› |
!== and <> have no difference. Both work in the same way.
PHP Logical Operators
A logical operator is a kind used in logic. In PHP, all logical operators return a boolean value.
| Operator | Name | Example | Result | |
|---|---|---|---|---|
| and | and | $a and $b | True if both $a and $b are true | Run Example ›› |
| && | and | $a && $b | True if both $a and $b are true | Run Example ›› |
| or | or | $a or $b | True if either $a or $b is true | Run Example ›› |
| || | or | $a || $b | True if either $a or $b is true | Run Example ›› |
| xor | xor | $a xor $b | True if either $a or $b is true, but not both | Run Example ›› |
| ! | not | !$a | True if $a is not true | Run Example ›› |
Note: We will discuss more about the if blocks we have used in this examples in the next lesson.
PHP Incrementing/Decrementing Operators
PHP's incrementing and decrementing operators are used to increment and decrement values respectively.
Note:
- Only strings and numbers (integers and floats) are affected by these operators.
- Arrays and objects are not affected.
- Decrementing null has no effect, but incrementing results in 1.
| Example | Name | Result | |
|---|---|---|---|
| ++$a | Pre-increment | Increments $a by one, then returns $a | Run Example ›› |
| $a++ | Post-increment | Returns $a, then increments $a by one. | Run Example ›› |
| --$a | Pre-decrement | Decrements $a by one, then returns $a | Run Example ›› |
| $a-- | Post-decrement | Returns $a, then decrements $a by one. | Run Example ›› |
PHP String Operators
There are two special string operators what help us to operate strings.
| Operator | Name | Example | Result | |
|---|---|---|---|---|
| . | Concatenation | $a . $b | Returns the concatenation of its right and left arguments | Run Example ›› |
| .= | Concatenation Assignment | $a .= $b | $a gets set to $a . $b | Run Example ›› |
PHP Array Operators
PHP array operators are used to perform operations on arrays.
| Operator | Name | Example | Result | |
|---|---|---|---|---|
| + | Union | $a + $b | Returns the union of $a and $b arrays. | Run Example ›› |
| += | Union Assignment | $a += $b | $a gets set to $a + $b | Run Example ›› |
| == | Equal | $a == $b | True if $a and $b has equal key/value pairs | Run Example ›› |
| === | Identical | $a === $b | True if $a and $b has equal key/value pairs in the same order and of same data type. | Run Example ›› |
| != | Not equal | $a != $b | True if $a and $b are not equal. | Run Example ›› |
| <> | Not equal | $a <> $b | True if $a and $b are not equal. | Run Example ›› |
| !== | Not identical | $a !== $b | True if $a and $b has different orders, different key/value pairs or values of different data types. | Run Example ›› |
Spaceship Operator
Spaceship Operator (<=>) is a combined comparison operator which was added in PHP 7. Integers, floats, and strings can be compared.
| When | Return Value |
|---|---|
| Either side are equal | 0 |
| The left side is greater | 1 |
| The right side is greater | -1 |
PHP Spaceship Operator - Integer Comparison
<?php
var_dump(1 <=> 1); // outputs 0
var_dump(1 <=> 2); // outputs -1
var_dump(2 <=> 1); // outputs 1
PHP Spaceship Operator - Float Comparison
<?php
var_dump(1.5 <=> 1.5); // outputs 0
var_dump(1.5 <=> 2.5); // outputs -1
var_dump(2.5 <=> 1.5); // outputs 1
PHP Spaceship Operator - String Comparison
<?php
var_dump('a' <=> 'a'); // outputs 0
var_dump('a' <=> 'b'); // outputs -1
var_dump('b' <=> 'a'); // outputs 1
var_dump('eat' <=> 'ear'); // outputs 1
PHP Spaceship Operator - Mixed Comparison
<?php
var_dump(1 <=> 2.5); // outputs -1
var_dump(2.5 <=> 1); // outputs 1
var_dump('1' <=> 1); // outputs 0
var_dump(1 <=> '2'); // outputs -1
var_dump('2' <=> 1); // outputs 1
Comparing strings like "dog" with an integer like 10 can return unexpected results.
Visit PHP Help group to get some help from experts.
