Single inheritance. PHP allows a class definition to inherit from another class, using the extends clause. Both member variables and member functions are inherited. • Multiple inheritance. PHP offers no support for multiple inheritance and no notion of interface inheritance asin Java. Each class inherits from, at most, one parent class (though a class may implement many interfaces). • Constructors. Every class can have one constructor function, which in PHP is called __construct() . Note that there are two underscore characters at the front of that function name. Constructors of parent classes arenot automatically called but must be invoked explicitly. • Destructors. PHP supports explicit destructor functions as of version 5. The destructor function of a class isalways called __destruct() . • Encapsulation/access control. PHP supports public, private, and protected properties and methods as of version