An abstract class can never be instantiated. Its sole purpose is to be extended (subclassed).If even a
single method is abstract, the whole class must be declared abstract. However, you can put non-abstract
methods in an abstract class.
An interface is a contractor what a class can do, without saying anything about how the class will do it.
Interfaces can be implemented by any class, from any inheritance tree. An interface can have only
abstract methods. All interface methods are implicitly public and abstract. All variables defined in an
interface must be public, static, and final i.e. interfaces can declare only constants, not instance variables.
An interface can extend one or more other interfaces. An interface cannot implement another interface or
class.
gregorymasila answered the question on January 24, 2018 at 17:39
- Java exception handling is managed by five keywords: state and discuss the role of each of the keywords.(Solved)
Java exception handling is managed by five keywords: state and discuss the role of each of the keywords.
Date posted: January 24, 2018. Answers (1)
- State four differences between Java applications and Java applets programming.(Solved)
State four differences between Java applications and Java applets programming.
Date posted: January 24, 2018. Answers (1)
- Explain the following terms:
i. Inheritance
ii. Encapsulation
iii. Polymorphism(Solved)
Explain the following terms:
Explain the following terms:
i. Inheritance
ii. Encapsulation
iii. Polymorphism
Date posted: January 24, 2018. Answers (1)
- By use of relevant examples, state the difference between
i. Statement and a block.
ii. Superclass and subclass
iii. Function overloading and overriding(Solved)
By use of relevant examples, state the difference between
i. Statement and a block.
ii. Superclass and subclass
iii. Function overloading and overriding
Date posted: January 24, 2018. Answers (1)
- State and explain four advantages of Java as an object oriented programming language.(Solved)
State and explain four advantages of Java as an object oriented programming language.
Date posted: January 24, 2018. Answers (1)
- Briefly describe what it means by business object analysis?(Solved)
Briefly describe what it means by business object analysis?
Date posted: January 24, 2018. Answers (1)
- Explain the benefits of the Unified Software Development Process (USDP).
(Solved)
Explain the benefits of the Unified Software Development Process (USDP).
Date posted: January 24, 2018. Answers (1)
- Define a model and briefly discuss the two types of models(Solved)
Define a model and briefly discuss the two types of models
Date posted: January 24, 2018. Answers (1)
- What is generalization? Give its advantage.(Solved)
What is generalization? Give its advantage.
Date posted: January 24, 2018. Answers (1)
- Briefly discuss UML and State significance of the Unified Modeling Language (UML) in object orientation (Solved)
Briefly discuss UML and State significance of the Unified Modeling Language (UML) in object orientation
Date posted: January 24, 2018. Answers (1)
- Outline some characteristics of a bad design? (Solved)
Outline some characteristics of a bad design?
Date posted: January 24, 2018. Answers (1)
- State the significance of analysis in object-oriented approach to systems development. (Solved)
State the significance of analysis in object-oriented approach to systems development.
Date posted: January 24, 2018. Answers (1)
- Define inheritance (Solved)
Define inheritance
Date posted: January 24, 2018. Answers (1)
- Briefly explain the main phases of USDP. (Solved)
Briefly explain the main phases of USDP.
Date posted: January 24, 2018. Answers (1)
- Most experts agree on a set of common principles of quality software: Briefly discuss the design principles stated below (Solved)
Most experts agree on a set of common principles of quality software: Briefly discuss the design principles stated below:
Reusability
Reliability
Robustness
Extensibility
Scalability
Date posted: January 19, 2018. Answers (1)
- Identify and discuss five aspects of human intelligence that could be used to characterize intelligent knowledge based systems.(Solved)
Identify and discuss five aspects of human intelligence that could be used to characterize intelligent knowledge based systems.
Date posted: January 9, 2018. Answers (1)
- Define a table.(Solved)
Define a table.
Date posted: January 3, 2018. Answers (1)
- After the system is operational, post-implementation evaluation performed. How is this
conducted and what is its significance?(Solved)
After the system is operational, post-implementation evaluation performed. How is this
conducted and what is its significance?
Date posted: December 18, 2017. Answers (1)
- What could form the source of information for developers of a new system?(Solved)
What could form the source of information for developers of a new system?
Date posted: December 18, 2017. Answers (1)
- In fact finding for systems development a number of techniques for investigating and
recording user requirements exist. State the four main techniques.(Solved)
In fact finding for systems development a number of techniques for investigating and
recording user requirements exist. State the four main techniques.
Date posted: December 18, 2017. Answers (1)