Sunday, February 3, 2008

Deadly Diamond of Death


Java doesn't support multiple inheritance because of Deadly Diamond of Death


Lets take an example:

1)Please take a notebook and a pencil, and start making a diagram

2)Suppose we have one class A, with a method printMe().

3) We have two subclass B and C, both inherits A and both Override printMe()

    A

B     C


Please connect B,and C to A by arrow.

4) Now Lets suppose we have one more class D, Now if Java supports multiple inheritance then we can write

class D inherits B,C

which means following :

     A


B         C


     D


Please connect D to both B and C by arrow.
Now if we look at the image, it actually a close structure with a "diamond kind of shape", along with this there is a big problem- {Please look at the image.}