Naming a unchecked exception by checked because it checks at

has a relationship denotes a whole part relatiosnship where a part cannot exist whithout the whole

is another one of the core concepts of object oriented programing it focuses on establishing a strong has a relationship between the three class

a composite object cannot exist on its own

composited object can have their own life cycle

aggregated object have their own life cycle

if one composition object is destroyed all its parts are also be deleted

means to provide a new implementation for a method in the subclass

must have at least tow methods

must have at one method

........ is known as compile time polymorphism

....... is known as runtime polymorphism

اسئلة ساهلة؟

the freature of one class may be inheritance by more than one class

the abstraction technique aim separate the implementation details of a class from its behavior