PHP 5 allows developers to declare constructor methods for classes. Classes which have a constructor method call this method on each newly-created object, so it is suitable for any initialization that the object may need before it is used. Parent constructors are not called implicitly. In order to run a parent constructor, a call to parent::__construct is required. ]]> For backwards compatibility, if PHP 5 cannot find a __construct function for a given class, it will search for the old-style constructor function, by the name of the class. Effectively, it means that the only case that would have compatibility issues is if the class had a method named __construct which was used for different semantics. PHP 5 introduces a destructor concept similar to that of other object-oriented languages, such as Java: When the last reference to an object is destroyed the object's destructor, which is a class method named __destruct that receives no parameters, is called before the object is freed from memory. name = "MyDestructableClass"; } function __destruct() { print "Destroying " . $this->name . "\n"; } } $obj = new MyDestructableClass(); ?> ]]> Like constructors, parent destructors will not be called implicitly by the engine. In order to run a parent destructor, one would have to explicitly call parent::__destruct in the destructor body.