# INTRODUCTION

# OPERATORS

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!