Abstract Classes In Java: Trivia Quiz!
(161).jpg "Abstract Classes In Java: Trivia Quiz!")
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- 1.What is an abstract class?
- A.
An abstract class is one without any child classes.
- B.
An abstract class is any parent class with more than one child class
- C.
An abstract class is a class which has at least one abstract method which cannot be instantiated.
- D.
Is a "base class"
- 2.What is an abstract method?
- A.
Is any method in an abstract class
- B.
Is a method which cannot be inherited
- C.
A method which is not implemented. The implementation for this method needs to be done in a non abstract class which extends this class.
- D.
Is a method in the child class that overrids a parent method
- 3.Can an abstract class define both abstract methods and non-abstract methods?
- A.
Yes - the child classes will inherit both
- B.
Yes - but the child classes do not inherit the abstract methods
- C.
No--it must have all abstract methods
- D.
No--it must have all one or the other
- 4.Does a subclass that extends an abstract class have to give implementation to all the abstract methods of the superclass?
- A.
Not necessarily if the sub class is going to be declared abstract
- B.
Yes-an abstract parent must have abstract children
- C.
No--an abstract parent mu have no children at all
- D.
Yes --all children of an abstract parent must be non-abstract
- 5.What is an interface?
- A.
A class with at least one abstract methods
- B.
A collection of abstract methods and constants
- C.
A super class with abstract method
- D.
A sub class with abstract method
- 6.What is Polymorphism in Java?
- A.
An object which has abstract method
- B.
Multiple inheritance - polymorphism
- C.
Hiding under a different name
- D.
The feature of deciding which overridden method will be used at the run time of a prgram
- 7.In order for the following code to be correct, what must be the type of the reference variable card? ____________________ card; card=new Valentine("Joe",14); card=new Holiday("Bob"); card=new Birthday("Emily",12);
- A.
Valentine
- B.
Holilday
- C.
Birthday
- D.
Card
- 8.Dynamic Binding or Late Binding is:
- A.
Connecting the method and the parameters
- B.
Because of overridden method and the use of the appropriate method during execution
- C.
Because of overloaded methods
- D.
When formal parameters and actual parameters differ
- 9.What determines what method is run in the following?Card crd=new Birthday("Lucinda",42);crd.greeting();
- A.
The reference type of the object reference variable
- B.
The type of the object
- C.
The type of the class
- D.
The Type of the constructors
- 10.Interfaces can contain _________________ and _____________________ and abstract classes can contain _____________________ , ______________________and at least ___ ____________________________________ __________________
- A.
Variables, constants,abstract methods and non abstract methods
- B.
Abstract methods,constants,instance variables, implemented methods and one abstract method
- C.
Constants, implemented methods, variables, abstract methods, overridden methods
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