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:

+

Addition

<?php
$x = 10;
$y = 6;

echo $x + $y;
?>

Output:

16

–	Subtraction

<?php
$x = 10;
$y = 6;

echo $x – $y;
?>

Output:

4

*	Multiplication

<?php
$x = 10;
$y = 6;

echo $x * $y;
?>

Output:

60

/

Division

<?php
$x = 10;
$y = 6;

echo $x / $y;
?>

Output:

%

Modulus

<?php
$x = 10;
$y = 6;

echo $x % $y;
?>

Output:

4

PHP Assignment Operators :

The PHP assignment operators are used with numeric values to write a value to a variable.

x = y

<?php
$x = 10;
echo $x;
?>

Output:

10

x += y

x = x + y

Addition

<?php
$x = 20;
$x += 100;

echo $x;
?>

Output:

120

x -= y

x = x – y

Subtraction

<?php
$x = 50;
$x -= 30;

echo $x;
?>

Output:

20

x *= y

x = x * y

Multiplication

<?php
$x = 10;
$y = 6;

echo $x * $y;
?>

Output:

60

x /= y

x = x / y

Division

<?php
$x = 10;
$x /= 5;

echo $x;
?>

Output:

2

x %= y

x = x % y

Modulus

<?php
$x = 15;
$x %= 4;

echo $x;
?>

Output:

3

PHP Comparison Operators

The PHP comparison operators are used to compare two values (number or string):

==

Equal

$x == $y

Returns true if $x is equal to $y

<?php
$x = 100;
$y = “100”;

var_dump($x == $y); // returns true because values are equal
?>

Output:

Bool(true)

!=

Not equal

$x != $y

Returns true if $x is not equal to $y

<?php
$x = 100;
$y = “100”;

var_dump($x != $y); // returns false because values are equal
?>

Output:

Bool(false)

>

Greater than

$x > $y

Returns true if $x is greater than $y

<?php
$x = 100;
$y = 50;

var_dump($x > $y); // returns true because $x is greater than $y
?>

Output:

bool(true)

<

Less than

$x < $y

Returns true if $x is less than $y

<?php
$x = 10;
$y = 50;

var_dump($x < $y); // returns true because $x is less than $y
?>

Output:

Bool(true)

>=

Greater than or equal to

$x >= $y

Returns true if $x is greater than or equal to $y

<?php
$x = 50;
$y = 50;

var_dump($x >= $y); // returns true because $x is greater than or equal to $y
?>

Output:

bool(true)

<=

Less than or equal to

$x <= $y

Returns true if $x is less than or equal to $y

<?php
$x = 50;
$y = 50;

var_dump($x <= $y); // returns true because $x is less than or equal to $y
?>

Output:

bool(true)

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.

++$x

Pre-increment

Increments $x by one, then returns $x

<?php
$x = 10;
echo ++$x;
?>

Output:

11

$x++

Post-increment

Returns $x, then increments $x by one

<?php
$x = 10;
echo $x++;
?>

Output:

10

–$x

Pre-decrement

Decrements $x by one, then returns $x

<?php
$x = 10;
echo –$x;
?>

Output:

9

$x–

Post-decrement

Returns $x, then decrements $x by one

<?php
$x = 10;
echo $x–;
?>

Output:

10

PHP Logical Operators

The PHP logical operators are used to combine conditional statements.

&&

And

$x && $y

True if both $x and $y are true

<?php
$x = 100;
$y = 50;

if ($x == 100 && $y == 50) {
echo “Hello world!”;
}
?>

Output:

Hello world!

||

Or

$x || $y

True if either $x or $y is true

<?php
$x = 100;
$y = 50;

if ($x == 100 || $y == 80) {
echo “Hello world!”;
}
?>

Output:

Hello world!

!

Not

!$x

True if $x is not true

<?php
$x = 100;

if ($x !== 90)

{
echo “Hello world!”;
}
?>

Output:

Hello world!