Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
429 views
in Technique[技术] by (71.8m points)

language agnostic - Why can't an object of abstract class be created?

Here is a scenario in my mind and I have googled, Binged it a lot but got the answer like

"Abstract class has not implemented method so, we cant create the object" "The word 'Abstract' instruct the compiler to not create an object of the class"

But in a simple class where we have all virtual method, able to create an object???

Also, we can define different access modified to Abstract class constructor like private, protected or public.

My search terminated to this question:

Why we can't create object of an Abstract class?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

An abstract type is defined largely as one that can't be created. You can create subtypes of it, but not of that type itself. The CLI will not let you do this.

An abstract class has a protected constructor (by default) allowing derived types to initialize it.

For example, the base-type Stream is abstract. Without a derived type where would the data go? What would happen when you call an abstract method? There would be no actual implementation of the method to invoke.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...