? PHP OOP Set Method

? Quick Overview

A setter method in PHP OOP is used to safely assign values to class properties while keeping them protected from direct access.

? Key Concepts

• Setter methods usually start with set.
• They control how data is assigned.
• They protect class properties using encapsulation.

? Syntax / Theory

Setter methods are especially useful when properties are declared as private or protected. They allow validation and rules before assignment.

? Code Example

// Class demonstrating setter and getter methods
// Setter method with validation
public function setAge($age) {
if ($age > 0) {
$this->age = $age;
} else {
echo "Invalid age";
}
}

// Getter method to access age
public function getAge() {
return $this->age;
}
}

$obj = new Student();
$obj->setAge(20);
echo $obj->getAge();
?>

? Live Output / Explanation

The setter ensures that only valid ages are stored. When setAge(20) is called, the value is accepted and printed using the getter method.

? Interactive Concept

Think of a setter as a security gate: all values must pass validation before entering the class.

? Use Cases

• Validating user input
• Applying business rules
• Protecting sensitive data