Question 1

The shaded header of the talkingAnimal() method accepts any type of Animal argument. Explain how this is possible.

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Question 2

Compare and contrast abstract classes and interfaces.

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Question 3

Why do many programmers consider multiple inheritance to be a difficult concept?

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Question 4

How is the Object class equals() method implemented?

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Question 5

The code above provides an example of an interface class. Explain the purpose and advantages of creating interfaces that store related constants.

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Question 6

Describe the two method types programmers of an abstract class can include.

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Question 7

public class Animal 
{ 
} 
public class Animal extends Object 
{ 
} 
The two class declarations above have identical outcomes. Explains why this is the case.

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{ 
} 
public class...

Question 8

The equals() method returns a boolean value indicating whether two objects are equal. Using the above code, will the two BankAccount objects be equal? Explain why or why not.

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Question 9

Give an example of how you can create an interface to have a class implement behavior from more than one parent.

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Question 10

When you create classes for others to use, why would you not want to provide the users with your source code in the files with .java extensions?

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Question 11

The AnimalReference application shown above contains a generic Animal reference variable into which you can assign concrete Animal objects. Explain how this example uses polymorphism and why it is important.

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Question 12

public interface FindTheError 
{ 
    void firstMethod(int anIntNum) 
   { 
        System.out.println("Did you find the error?"); 
   } 
} 
What is the problem with the above interface? How would you correct the interface?

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{ 
    void firstMethod(int anIntNum)...

Question 13

When you create a useful, extendable superclass, you and other future programmers gain what advantages?

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Question 14

An array can be created to reserve space for references to objects. Using the code above, explain how an array of superclass references can hold subclass references.

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Question 15

public abstract class Car 
{ 
    private String model; 
    public abstract void color(); 
    public String getName() 
    { 
        return model; 
     } 
     public void setName(String carModel) 
     { 
        model = carModel; 
      } 
} 
Using the code above, would it be possible to create a class in which you declare a Car object with the statement Car myCar = new Car("Honda"); ? 
Explain why or why not.

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{ 
    private String...

Question 16

public abstract class Car 
{ 
    private String model; 
    public abstract void color(); 
    public String getModel() 
    { 
         return model; 
     } 
    public void setModel(String modelName) 
    { 
         model = modelName; 
     } 
} 
​ 
public class Honda extends Car 
{ 
    public void color() 
    { 
System.out.println("red"); 
    } 
} 
​ 
public class Ford extends Car 
{ 
    public void color() 
    { 
      System.out.println("blue"); 
    } 
} 
​ 
public class MyCars 
{ 
    public static void main(String[] args) 
    { 
       Honda myHonda = new Honda(); 
       Ford myFord = new Ford(); 
  myHonda.setModel("My Honda is "); 
       myFord.setModel("My Ford is "); 
  System.out.print(myHonda.getModel()); 
  myHonda.color(); 
  System.out.print(myFord.getModel()); 
  myFord.color(); 
    } 
} 
In the above code, the myHonda.getModel() and myHonda.color() method calls produce different output from when the same methods are used with myFord . Explain why this is the case.

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{ 
    private String...

Question 17

public abstract class Shape 
{ 
    private int length; 
    private int width; 
    private int height; 
    ----Code here---- 
} 
Using the above code, create the statement in the place indicated that will create an abstract calculateArea() method in the abstract Shape class.

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{ 
    private int...

Question 18

What are the advantages to creating a useful, extendable superclass?

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Quiz 11: Advanced Inheritance Concepts