In PHP, variables can store various types of data, each with its own unique behavior and capabilities.
PHP supports several data types, including:
- String
- Integer
- Float (also known as double)
- Boolean
- Array
- Object
- NULL
- Resource
Getting the Data Type
You can find out the data type of any variable using the var_dump()
function.
Example:
$price = 2000.50; var_dump($price);
PHP String
A string is a sequence of characters, like “Hello, world!”.
Strings can be enclosed in single or double quotes.
Example:
$brand1 = "Nike"; $brand2 = 'Adidas'; var_dump($brand1); echo "<br>"; var_dump($brand2);
PHP Integer
An integer is a non-decimal number that falls within a certain range.
Rules for integers:
- An integer must have at least one digit.
- An integer must not have a decimal point.
- An integer can be either positive or negative.
- Integers can be specified in decimal (base 10), hexadecimal (base 16), octal (base 8), or binary (base 2) notation.
Example:
$quantity = 1500; var_dump($quantity);
PHP Float
A float (or double) is a number with a decimal point or in exponential form.
Example:
$weight = 75.5; var_dump($weight);
PHP Boolean
A Boolean represents a binary state: TRUE
or FALSE
.
Example:
$isAvailable = true; var_dump($isAvailable);
Booleans are often used in conditional statements.
PHP Array
An array can store multiple values in one variable.
Example:
$brands = array("Tesla", "Ford", "Chevrolet"); var_dump($brands);
PHP Object
Object-oriented programming revolves around classes and objects. A class is a blueprint, and an object is an instance of that class.
Example:
class Car { public $brand; public $model; public function __construct($brand, $model) { $this->brand = $brand; $this->model = $model; } public function description() { return "My car is a " . $this->brand . " " . $this->model . "."; } } $myCar = new Car("Ferrari", "488 Spider"); var_dump($myCar);
PHP NULL Value
A variable with the NULL
data type has no value assigned to it.
Example:
$model = "Mustang"; $model = null; var_dump($model);
Changing Data Type
PHP automatically changes the data type based on the value assigned to a variable.
Example:
$quantity = 20; var_dump($quantity); $quantity = "twenty"; var_dump($quantity);
You can also explicitly change the data type using type casting.
Example:
$count = 10; $count = (string) $count; var_dump($count);