? PHP OOP __wakeup() Method

? Quick Overview

The __wakeup() magic method in PHP OOP is automatically executed when an object is restored using unserialize(). It is commonly used to reinitialize resources like database connections.

? Key Concepts

• Triggered during object unserialization
• Used to restore object state
• Works alongside __sleep()

? Syntax & Theory

Serialization converts an object into a string for storage. When the object is unserialized, __wakeup() prepares it for use again.

? Code Example

// PHP class demonstrating __sleep() and __wakeup()
link = "Database Connection Established";
echo $this->link . "
";
}

public function __sleep() {
// Only selected properties are serialized
return ['host','user'];
}

public function __wakeup() {
// Reinitialize resources after unserialization
$this->link = "Database Reconnected";
echo $this->link . "
";
}
}

$conn = new Connection();
$serialized = serialize($conn);
$restored = unserialize($serialized);
?>

? Live Output / Explanation

When the object is unserialized, PHP automatically calls __wakeup(), restoring the database connection message.

? Use Cases

• Reconnecting database handles
• Restoring file pointers
• Reinitializing API clients