Introduction to Java Programming and Data Structures, Comprehensive Version (11th Edition)
Introduction to Java Programming and Data Structures, Comprehensive Version (11th Edition)
11th Edition
ISBN: 9780134670942
Author: Y. Daniel Liang
Publisher: PEARSON
Question
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Chapter 13.2, Problem 13.2.1CP
Program Plan Intro

a)

“abstract” class:

An abstract class is a class which may or may not include abstract methods and cannot be instantiated but rather it can be sub classed.

Legal “abstract” class:

  • The conditions for a class to be considered as legal abstract class are mentioned below:
    • If a class includes abstract methods, then the class must be declared as abstract.
    • The abstract method that is declared within the abstract class must be declared without braces and followed by a semicolon.

Example of a Legal “abstract” class:

The example of a legal abstract class is mentioned below:

public abstract class GraphicRectangle {

//declare fields

//declare methods

abstract void drawRectangle();

}

Given code:

//class definition

class A {

  //declaration of an abstract method

  abstract void unfinished() {

  }

//end of class

}

Program Plan Intro

b)

“abstract” class:

An abstract class is a class which may or may not include abstract methods and cannot be instantiated but rather can be sub classed.

Legal “abstract” class:

The conditions for a class to be considered as legal abstract class are mentioned below:

  • If a class includes abstract methods, then the class must be declared as abstract.
  • The abstract method that is declared within the abstract class must be declared without braces and followed by a semicolon.

Example of a Legal “abstract” class:

The example of a legal abstract class is mentioned below:

public abstract class GraphicRectangle {

//declare fields

//declare methods

abstract void drawRectangle();

}

Given code:

//class definition

public class abstract A {

  //declaration of an abstract method

  abstract void unfinished();

//end of class

}

Program Plan Intro

c)

“abstract” class:

An abstract class is a class which may or may not include abstract methods and cannot be instantiated but rather can be sub classed.

Legal “abstract” class:

The conditions for a class to be considered as legal abstract class are mentioned below:

  • If a class includes abstract methods, then the class must be declared as abstract.
  • The abstract method that is declared within the abstract class must be declared without braces and followed by a semicolon.

Example of a Legal “abstract” class:

The example of a legal abstract class is mentioned below:

public abstract class GraphicRectangle {

//declare fields

//declare methods

abstract void drawRectangle();

}

 Given code:

//class definition

class A {

  //declaration of an abstract method

  abstract void unfinished();

   //end of class

   }

Program Plan Intro

d)

“abstract” class:

An abstract class is a class which may or may not include abstract methods and cannot be instantiated but rather can be sub classed.

Legal “abstract” class:

The conditions for a class to be considered as legal abstract class are mentioned below:

  • If a class includes abstract methods, then the class must be declared as abstract.
  • The abstract method that is declared within the abstract class must be declared without braces and followed by a semicolon.

Example of a Legal “abstract” class:

The example of a legal abstract class is mentioned below:

public abstract class GraphicRectangle {

//declare fields

//declare methods

abstract void drawRectangle();

}

 Given code:

//class definition

abstract class A {

        //declaration of a protected method

         protected void unfinished();

   //end of class

}

Program Plan Intro

e)

“abstract” class:

An abstract class is a class which may or may not include abstract methods and cannot be instantiated but rather can be sub classed.

Legal “abstract” class:

The conditions for a class to be considered as legal abstract class are mentioned below:

  • If a class includes abstract methods, then the class must be declared as abstract.
  • The abstract method that is declared within the abstract class must be declared without braces and followed by a semicolon.

Example of a Legal “abstract” class:

The example of a legal abstract class is mentioned below:

public abstract class GraphicRectangle {

//declare fields

//declare methods

abstract void drawRectangle();

}

 Given code:

//class definition

abstract class A {

        //declaration of an abstract method

          abstract void unfinished();

//end of class

}

Program Plan Intro

f)

“abstract” class:

An abstract class is a class which may or may not include abstract methods and cannot be instantiated but rather can be sub classed.

Legal “abstract” class:

The conditions for a class to be considered as legal abstract class are mentioned below:

  • If a class includes abstract methods, then the class must be declared as abstract.
  • The abstract method that is declared within the abstract class must be declared without braces and followed by a semicolon.

Example of a Legal “abstract” class:

The example of a legal abstract class is mentioned below:

public abstract class GraphicRectangle {

//declare fields

//declare methods

abstract void drawRectangle();

}

Given code:

//class definition

abstract class A {

        //declaration of an abstract method

          abstract int unfinished();

//end of class

}

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Which of the following statements about abstract base classes is true?   a. abstract base classes may contain data.   b. abstract base classes may not contain implementations of methods.   c. abstract base classes must declare all methods as abstract.   d. abstract base classes must declare all data members not given values as abstract
Which of the following statements are true. a) An abstract method contains a signature but no code implementation. b) We cannot create an instance of an abstract class by using the new operator. c) We can derive classes from an abstract class, but we must provide code to implement all of the abstract methods. d) All of the above statements are true.
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Chapter 13 Solutions

Introduction to Java Programming and Data Structures, Comprehensive Version (11th Edition)

Ch. 13.4 - How do you create a Calendar object for the...Ch. 13.4 - For a Calendar object c, how do you get its year,...Ch. 13.5 - Prob. 13.5.1CPCh. 13.5 - Prob. 13.5.2CPCh. 13.5 - Prob. 13.5.3CPCh. 13.5 - Prob. 13.5.4CPCh. 13.6 - Prob. 13.6.1CPCh. 13.6 - Prob. 13.6.2CPCh. 13.6 - Can the following code be compiled? Why? Integer...Ch. 13.6 - Prob. 13.6.4CPCh. 13.6 - What is wrong in the following code? public class...Ch. 13.6 - Prob. 13.6.6CPCh. 13.6 - Listing 13.5 has an error. If you add list.add...Ch. 13.7 - Can a class invoke the super.clone() when...Ch. 13.7 - Prob. 13.7.2CPCh. 13.7 - Show the output of the following code:...Ch. 13.7 - Prob. 13.7.4CPCh. 13.7 - What is wrong in the following code? public class...Ch. 13.7 - Show the output of the following code: public...Ch. 13.8 - Prob. 13.8.1CPCh. 13.8 - Prob. 13.8.2CPCh. 13.8 - Prob. 13.8.3CPCh. 13.9 - Show the output of the following code: Rational r1...Ch. 13.9 - Prob. 13.9.2CPCh. 13.9 - Prob. 13.9.3CPCh. 13.9 - Simplify the code in lines 8285 in Listing 13.13...Ch. 13.9 - Prob. 13.9.5CPCh. 13.9 - The preceding question shows a bug in the toString...Ch. 13.10 - Describe class-design guidelines.Ch. 13 - (Triangle class) Design a new Triangle class that...Ch. 13 - (Shuffle ArrayList) Write the following method...Ch. 13 - (Sort ArrayList) Write the following method that...Ch. 13 - (Display calendars) Rewrite the PrintCalendar...Ch. 13 - (Enable GeometricObject comparable) Modify the...Ch. 13 - Prob. 13.6PECh. 13 - (The Colorable interface) Design an interface...Ch. 13 - (Revise the MyStack class) Rewrite the MyStack...Ch. 13 - Prob. 13.9PECh. 13 - Prob. 13.10PECh. 13 - (The Octagon class) Write a class named Octagon...Ch. 13 - Prob. 13.12PECh. 13 - Prob. 13.13PECh. 13 - (Demonstrate the benefits of encapsulation)...Ch. 13 - Prob. 13.15PECh. 13 - (Math: The Complex class) A complex number is a...Ch. 13 - (Use the Rational class) Write a program that...Ch. 13 - (Convert decimals to fractious) Write a program...Ch. 13 - (Algebra: solve quadratic equations) Rewrite...Ch. 13 - (Algebra: vertex form equations) The equation of a...
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