PHP OOP Access Modifiers

PHP OOP Access Modifiers (public, private, protected)

PHP OOP Access Modifiers control the visibility of properties and methods in a class.

1. Types of Access Modifiers in PHP

Modifier	Accessible Inside Class	Accessible Outside Class	Accessible in Child Class
public	Yes	Yes	Yes
private	Yes	No	No
protected	Yes	No	Yes

public (open for all)

Anything public can be accessed from anywhere.

Example:

private (only inside same class)

Private properties/methods cannot be accessed from outside or by child classes.

Wrong (will cause error):

Access using a public method:

protected (inside class + child class)

Protected can be accessed from:

same class
inherited (child) classes
NOT accessible from outside

Example:

class ParentClass {
protected $value = "Hello";
}

class ChildClass extends ParentClass {
public function show() {
echo $this->value; // Works
}
}

$obj = new ChildClass();
$obj->show();

// Outside access (not allowed)
// echo $obj->value; // ERROR

class ParentClass {

protected $value = "Hello";

}

class ChildClass extends ParentClass {

public function show() {

echo $this->value; // Works

}

$obj = new ChildClass();

$obj->show();

// Outside access (not allowed)

// echo $obj->value; // ERROR

Full Example: All 3 Modifiers Together

class Demo {
public $publicVar = "Public";
private $privateVar = "Private";
protected $protectedVar = "Protected";

public function showValues() {
echo $this->publicVar . "<br>";
echo $this->privateVar . "<br>";
echo $this->protectedVar . "<br>";
}
}

$demo = new Demo();
$demo->showValues(); // Works

echo $demo->publicVar; // Works
// echo $demo->privateVar; // ERROR
// echo $demo->protectedVar; // ERROR

class Demo {

public $publicVar = "Public";

private $privateVar = "Private";

protected $protectedVar = "Protected";

public function showValues() {

echo $this->publicVar . "<br>";

echo $this->privateVar . "<br>";

echo $this->protectedVar . "<br>";

}

$demo = new Demo();

$demo->showValues(); // Works

echo $demo->publicVar; // Works

// echo $demo->privateVar; // ERROR

// echo $demo->protectedVar; // ERROR

Why Access Modifiers Are Important?

Improve security
Prevent accidental changes
Control how data is accessed
Make code clean and professional
Essential for real OOP projects
Used heavily in Laravel

Summary Table (Easy to Remember)

Modifier	Meaning
public	Anyone can access
private	Only inside the class
protected	Class + child subclass

PHP OOP Access Modifiers