TAW_12 Chapter 3, Inheritance and casting

Question 1

How many super classes can a class have?

Answer 1

A class may only inherit from one super class, but that super class may have inherited from a super class as well

Question 2

Can signatures be changed when redefining a method?

Answer 2

No

Question 3

When redefining a method should I specify a signature?

Answer 3

No, because the signature is inherited from the super class

Question 4

If when redefining a method I just want to add code rather than replace it, how can I call the super class method in my redefinition?

Answer 4

super->method

Question 5

Can a constructor be redefined?

Answer 5

No, you don’t need to do that because you can create a constructor independent of the super class constructor. It can have it’s own signature. YOU MUST CALL the SUPER->CONSTRUCTOR as part of your new instance constructor. You may need to find the previous super class signature to make sure you supply the parameters

Question 6

What symbol is used in UML to denote Protected?

Answer 6

#

Question 7

Protected components are visible…?

Answer 7

In the class and all subclasses

Question 8

How can a subclass access private attributes of the superclass?

Answer 8

Using public or protected methods of the superclass

Question 9

Can a subclass have its own class-constructor?

Answer 9

Yes, and it does not need to call the super-class class-constructor as that is called automatically

Question 10

What is the downcast syntax?

Answer 10

?=