Author Question: Virtual Private Networks are hardware or software that controls access between networks. Indicate ... (Read 610 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 effects of organophosphate poisoning are referred to by using the abbreviations “SLUD” or “SLUDGE,” It stands for: salivation, lacrimation, urination, defecation, GI upset, and emesis.

Did you know?

Barbituric acid, the base material of barbiturates, was first synthesized in 1863 by Adolph von Bayer. His company later went on to synthesize aspirin for the first time, and Bayer aspirin is still a popular brand today.

Did you know?

The Food and Drug Administration has approved Risperdal, an adult antipsychotic drug, for the symptomatic treatment of irritability in children and adolescents with autism. The approval is the first for the use of a drug to treat behaviors associated with autism in children. These behaviors are included under the general heading of irritability and include aggression, deliberate self-injury, and temper tantrums.

Did you know?

Autoimmune diseases occur when the immune system destroys its own healthy tissues. When this occurs, white blood cells cannot distinguish between pathogens and normal cells.

Did you know?

Patients who have been on total parenteral nutrition for more than a few days may need to have foods gradually reintroduced to give the digestive tract time to start working again.

For a complete list of videos, visit our video library