Question 1

Are private fields and methods of the superClass inherited in the subClass.

Accepted Answer

NO. Private members of the superclass are not inherited.

Question 2

If a subclass constructor does not explicitly call a superclass constructor, what will Java automatically do?

Accepted Answer

If a subclass constructor does not explicitly call a superclass constructor, Java will automatically call the superclass's default constructor, OR NO-ARG constructor, JUST BEFORE the code in the subclass's constructor executes.

Question 3

Can a method be oeverloaded and simultaneously be overriding a method in a superclass?

Accepted Answer

Yes. For example, if the superclass has the method int getApples(), then the subclass can have the methods

Question 4

has a is a part of what concept?

Accepted Answer

aggregation

Question 5

is a is a part of what concept?

Accepted Answer

inheritance

Question 6

When a sub class inherits fields and methods from a super class, they are not included in the sub class.

Accepted Answer

true

Question 7

What keyword indicates that a subclass inherits from a super class?

Accepted Answer

extends

Question 8

In a UML diagram, how do we indicate that a subclass extends a super class?

Accepted Answer

We use an open arrow head pointing from the subclass to the super class.

Question 9

We can say that a subclass is a specialized version of the SuperClass.

Accepted Answer

True

Question 10

Given two classes, Auto() and SportsCar() which extends Auto(), when a new SportsCar object is created, java will first create what object?

Accepted Answer

First an object of the superClass Auto() is created, then the subclass SportsCar() object.

Question 11

Can private members of the superclass be accessed by the subclass?

Accepted Answer

NO. Private members of the superclass are not inherited.

Question 12

Given a superClass with a private field numHours, and a subclass called Student, Is the following statement syntactically correct?SubClass child = new SubClass();println(My child studies  + child.numHours +  hours a day.)

Accepted Answer

NO. The sub class child cannot inherit private fields or methods from the superclass.

Question 13

SuperClass constructors ARE or ARE NOT inherited.

Accepted Answer

NOT. Constructors are NOT inherited.

Question 14

When a subclass is instantiated, the superclass _____________ constructor is executed first.

Accepted Answer

default

Question 15

When a subclass is instantiated, what is instantiated first?

Accepted Answer

The superclass default constructor. Think of this as The parent has to be created before the child is created.

Question 16

What does the super keyword refer to?

Accepted Answer

The super() keyword refers to an objects superclass, and it can be used to explicitly call the constructor of the superclass.

Question 17

What happens if you have written your own constructor in the superclass, and you omit the default constructor...

Accepted Answer

You can add a no-arg constructor in the superclass, or when writing the subclass constructor, issue a call to the superclass constructor.

Question 18

Must the call to the superclass constructor be the first java statement in the subclass constructor?

Accepted Answer

Absolutely.

Question 19

If the superclass does not have a default no-arg constructor, what must happen?

Accepted Answer

Every subclass must explicitly invoke the superclass constructor using the keyword SUPER.

Question 20

How can a subclass method invoke the overridden method found in the superclass?

Accepted Answer

By using the super keyword

Question 21

What is a protected Member?

Accepted Answer

Protected members of a class may be accessed by methods in a subclass and by methods in the same package as the class. This limits what has access to the member.

Question 22

In a UML diagram how is a protected member designated?

Accepted Answer

#

Question 23

How do we prevent a method from being overridden in the superclass by a subclass?

Accepted Answer

By using the final modifier.public final void message();

Question 24

What is the Object class?

Accepted Answer

The Java API has a class named object, which all other classes directly or indirectly inherit from. Tow of the most useful members that classes inherit are the toString and equals methods.

Question 25

Why does every class have a toString or equals method?

Accepted Answer

because every class inherits from the object class.

Question 26

Can static members be overridden?

Accepted Answer

NO. Static members are a property of a class and therefore cannot be overridden.

Question 27

What is the difference between overloading and overriding?

Accepted Answer

Overloading is when a method has the same name as one or more other methods, but a different parameter list. Although overloaded methods have the same name, they have different signatures. When a method OVERRIDES another method however, they both have the same signature.

Question 28

Is this syntactically correct?if (dogs[4] == null){..}

Accepted Answer

Yes.

[7]Lecture 10: Inheritance

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