What are magic methods in PHP?

Magic methods in PHP are special methods that are called automatically under certain circumstances. Their names start with two underscores (__).

List of main magic methods:

• __construct(): Called when a new object is created.
• __destruct(): Called when an object is destroyed.
• __call($name, $arguments): Called when attempting to invoke an inaccessible or non-existent method of an object.
• __callStatic($name, $arguments): Called when attempting to invoke an inaccessible or non-existent static method.
• __get($name): Called when attempting to access an inaccessible property of an object.
• __set($name, $value): Called when attempting to set a value to an inaccessible property of an object.
• __isset($name): Called when using isset() or empty() on an inaccessible property.
• __unset($name): Called when using unset() on an inaccessible property.
• __sleep(): Called before serialization, returns an array of property names for serialization.
• __wakeup(): Called after deserialization.
• __toString(): Allows the object to behave as a string when used in a string context.
• __invoke($args): Called when the script tries to invoke the object as a function.
• __set_state(array $properties): Called when exporting an object with var_export().
• __clone(): Called after cloning an object to set up the clone.
• __serialize(): Called during serialization, returns an array of data for serialization.
• __unserialize(array $data): Called during deserialization, receives data from __serialize().

Example of using __construct and __destruct:

<?php
class Example {
    public function __construct() {
        echo "Object created\n";
    }

    public function __destruct() {
        echo "Object destroyed\n";
    }
}

$obj = new Example();
unset($obj); // Forcibly destroys the object
?>

Example of using __get and __set:

<?php
class DataStore {
    private $data = [];

    public function __set($name, $value) {
        $this->data[$name] = $value;
    }

    public function __get($name) {
        if (array_key_exists($name, $this->data)) {
            return $this->data[$name];
        }
        return null; // Or throw an exception
    }
}

$store = new DataStore();
$store->name = "Alice"; // Calls __set
echo $store->name; // Calls __get
?>