Author Question: Virtual Private Networks are hardware or software that controls access between networks. Indicate ... (Read 774 times)

Marty

  • Hero Member
  • *****
  • Posts: 553
Virtual Private Networks are hardware or software that controls access between networks.
 
  Indicate whether the statement is true or false

Question 2

Describe the difference between concrete and abstract classes and give an example for each.
 
  What will be an ideal response?



smrtceo

  • Sr. Member
  • ****
  • Posts: 344
Answer to Question 1

FALSE

Answer to Question 2

An abstract class is one that cannot have instances, while a concrete class can. If a class has all the required attributes and operations that we expect from an object, then it is concrete. If it has only a subset, then it is abstract and we need a more specialized class. For example Art is an abstract class because we have found it to be too general to satisfactorily represent a specific work of art. Saying that somebody is interested in art does not explain enough. At best, it prompts a question: what kind of art? The answer might be music, literature, painting, theatre, etc. On the other hand, the Literature class has enough attributes to be concrete. That is, we believe it can properly represent an actual literary work.



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question


 

Did you know?

The first war in which wide-scale use of anesthetics occurred was the Civil War, and 80% of all wounds were in the extremities.

Did you know?

In the ancient and medieval periods, dysentery killed about ? of all babies before they reach 12 months of age. The disease was transferred through contaminated drinking water, because there was no way to adequately dispose of sewage, which contaminated the water.

Did you know?

After 5 years of being diagnosed with rheumatoid arthritis, one every three patients will no longer be able to work.

Did you know?

The newest statin drug, rosuvastatin, has been called a superstatin because it appears to reduce LDL cholesterol to a greater degree than the other approved statin drugs.

Did you know?

The largest baby ever born weighed more than 23 pounds but died just 11 hours after his birth in 1879. The largest surviving baby was born in October 2009 in Sumatra, Indonesia, and weighed an astounding 19.2 pounds at birth.

For a complete list of videos, visit our video library