PHP Data Types and Operators

PHP Data Types

Variables can store data of different types, and different data types can do different things.

PHP supports the following data types:

• String
• Integer
• Float (floating point numbers - also called double)
• Boolean
• Array
• Object
• NULL
• Resource

PHP String

A string is a sequence or arrangement of characters known as string, like "Hello testing!".

<?php
$x = 'Hello world!';
$y = 'Hello world!'; //we can also use double quote

echo $x;
echo '';
echo $y;
?>

Output : Hello world! Hello world!

PHP Integer

An integer data type is a non-decimal number between -2,147,483,648 and 2,147,483,647.

<?php
$x = 10;
var_dump($x);
?>

output: int(10)

PHP Float

A float (floating point number) is a number with a decimal point or a number in exponential form.

<?php
$x = 10.365;
var_dump($x);
?>

Output: float(10.365)

PHP Boolean

This type only True & False

 

PHP Array

<?php
$al= array("A","B","C");
var_dump($al);
?>

PHP Object

Object is an instantiation of a class

<?php
//Car is a class
class Car {
  public $color;
  public $model;
  public function __construct($color, $model) {
    $this->color = $color;
    $this->model = $model;
  }
  public function message() {
    return "My car is a " . $this->color . " " . $this->model . "!";
  }
}
// $myCar is an object
$myCar = new Car("black", "Volvo");
echo $myCar -> message();
echo "
";
$myCar = new Car("red", "Toyota");
echo $myCar -> message();
?>

PHP NULL Value

Null is a special data type which can have only one value: NULL.

<?php
$x = "Hello test!";
$x = null;
var_dump($x);
?>

PHP Resource

The special resource type is not an actual data type. It is the storing of a reference to functions and resources external to PHP.

 

PHP Operators

• Arithmetic operators
• Assignment operators
• Comparison operators
• Increment/Decrement operators
• Logical operators
• String operators
• Array operators
• Conditional assignment operators

1- Arithmetic operators

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

2- PHP Assignment Operators

Assignment	Same	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

 

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
<=>	Spaceship	$x <=> $y	Returns an integer less than, equal to, or greater than zero, depending on if $x is less than, equal to, or greater than $y. Introduced in PHP 7.

 

PHP Increment / Decrement Operators

The PHP increment operators are used to increment 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

 

PHP Logical Operators

Operator	Name	Example
and	And	$x and $y
or	Or	$x or $y
xor	Xor	$x xor $y
&&	And	$x && $y
||	Or	$x || $y
!	Not	!$x

 

PHP Conditional Assignment Operators

Operator	Name	Example
?:	Ternary	$x = expr1 ? expr2 : expr3
??	Null coalescing	$x = expr1 ?? expr2

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