What are the advantages of Object C over C ++?

Possible duplicate:
What are the advantages of using Objective-C over C ++

Could you please tell me what are the advantages of objective c over C ++? After reading the c? I think C ++ has the same, if not similar functionality.

And why should a project like Webkit have to use both C ++ and Objective C? I understand that the general Webkit code is in C ++, whereas the MacOS portion mentioned is in the c object.

Thanks for any pointers.