Q about inheritance and overriding

  • Thread starter Thread starter Rexel
  • Start date Start date
R

Rexel

Lets see if I have got this correct.

I have a class A which has a method: Compute.
I create a new class B which inherits from A.
Class B now has all the methods of class A.
If in the code I use:

Dim b AS New B
b.Compute()

this causes the code in A.Compute to execute. Right?

Now I add a method to B which is also named Compute,
but in Class B I use the keyword Override when creating
the method.
If I again use the same code,i.e.,

Dim b AS New B
b.Compute()

this time the code in B.Compute will run and the code
in A.Compute is skipped.
Is this correct?

What if I don't use the keyword Override for Compute method
in Class B?
What happens now when I call b.Compute?
Which method is run? B.Compute, A.Compute, or both?

My confusion on this subject is because when you create
a form it has a New method, thus:

Private Sub New()
MyBase.New()
'
End Sub

So the base from which this form was derived also has a
method called New.
Why isn't Override used here?
 
* Rexel said:
I have a class A which has a method: Compute.
I create a new class B which inherits from A.
Class B now has all the methods of class A.
If in the code I use:

Dim b AS New B
b.Compute()

this causes the code in A.Compute to execute. Right?

Now I add a method to B which is also named Compute,
but in Class B I use the keyword Override when creating
the method.
If I again use the same code,i.e.,

Dim b AS New B
b.Compute()

this time the code in B.Compute will run and the code
in A.Compute is skipped.
Is this correct?
Click to expand...

Why not test it yourself?
What if I don't use the keyword Override for Compute method
in Class B?
What happens now when I call b.Compute?
Which method is run? B.Compute, A.Compute, or both?

My confusion on this subject is because when you create
a form it has a New method, thus:

Private Sub New()
MyBase.New()
'
End Sub

So the base from which this form was derived also has a
method called New.
Why isn't Override used here?
Click to expand...

There is a difference between simple methods and constructors:
Constructors don't get inherited.
 
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