PHP OOP Static Properties

🧲 PHP OOP – Static Properties

In PHP OOP Static Properties belongs to the class, not to individual objects.

✔ Shared by all objects
✔ Accessed using ClassName::$property
✔ Declared with static keyword

1️⃣ Basic Static Property Example

You don’t need to create an object.

2️⃣ Access Static Property Inside Class

Use self::$property inside the same class.

3️⃣ Modify Static Property

4️⃣ All Objects Share Same Static Property

All objects update one shared variable.

5️⃣ Static Property with Inheritance

Child class inherits static properties.

6️⃣ Override Static Property in Child

Each class keeps its own version.

7️⃣ Late Static Binding with Static Properties

Use static::$property for overriding behavior.

8️⃣ Wrong: Cannot Use `$this` with Static Property

Because $this refers to an object, not the class.

9️⃣ Practical Use Case – Configuration

🔟 Practical Use Case – Auto Incrementing ID

class Student {
public static $id = 1;
public $studentId;

public function __construct() {
$this->studentId = self::$id++;
}
}

$s1 = new Student();
$s2 = new Student();

echo $s1->studentId; // 1
echo $s2->studentId; // 2

class Student {

public static $id = 1;

public $studentId;

public function __construct() {

$this->studentId = self::$id++;

}

$s1 = new Student();

$s2 = new Student();

echo $s1->studentId; // 1

echo $s2->studentId; // 2

🎯 Summary (Easy to Remember)

Feature	Meaning
static property	Belongs to class, not object
Access using	`ClassName::$property`
All objects share	✔ Yes
Cannot use `$this`	✔
Good for	Counters, settings, shared data

PHP OOP Static Properties