Question 6

Which of the following is true about a concrete class?

A concrete class may be extended.

A concrete class may be instantiated.

A concrete may NOT contain abstract methods.

All of the above.

None of the above.

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Question 7

Which of the following is true?

A class extends exactly one other class and may implement any number of interfaces.

A class may extend at most one concrete class, may extend any number of abstract classes, and may implement any number of interfaces.

A class may extend one concrete class and also one abstract class, and may implement any number of interfaces.

A class may extend exactly one other class, OR may implement any number of interfaces, but not both.

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Question 8

Given the following declarations,

public class Parent { ... } public class Child extends Parent implements Wizard { ... } public class Grandchild extends Child { ... }

Which of the following is NOT true?

Child "Is-A" Wizard

Parent "Is-A" Wizard

Grandchild "Is-A" Child

Grandchild "Is-A" Parent

Grandchild "Is-A" Wizard

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Question 9

In Java a class can inherit members from more than 1 super class.

True

False

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Question 10

Given the following definition: public class Alpha implements Freezable {...} And the following client code: Freezable f = new Alpha(); Which is true?

The variable f has static type Freezable and dynamic type Freezable

The variable f has static type Freezable and dynamic type Alpha

The variable f has static type Alpha and dynamic type Alpha

The variable f has static type Alpha and dynamic type Freezable

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Question 11

Which of the following creates a new data type?

an abstract class definition

a concrete class definition

an interface definition

All of the above.

None of the above.