In the following code, I create a base abstract class Base. I want all the classes that inherit from Base to provide the name property, so I made this property an @abstractmethod. Then I created a subclass of Base, called Base_1, which is meant to supply some functionality, but still remain abstract. There is no … Read more
I’d like to test an abstract class. Sure, I can manually write a mock that inherits from the class. Can I do this using a mocking framework (I’m using Mockito) instead of hand-crafting my mock? How? 12 Answers 12
Why is it possible to write constructor for an abstract class in C#? As far as I know we can’t instantiate an abstract class.. so what is it for? You can’t instantiate the class, right? 14 Answers 14
Because I am used to the old ways of duck typing in Python, I fail to understand the need for ABC (abstract base classes). The help is good on how to use them. I tried to read the rationale in the PEP, but it went over my head. If I was looking for a mutable … Read more
What is an “abstract class” in Java? 14 Answers 14
Please explain when I should use a PHP interface and when I should use an abstract class? How I can change my abstract class in to an interface? 11 Answers 11
How can I make a class or method abstract in Python? I tried redefining __new__() like so: class F: def __new__(cls): raise Exception(“Unable to create an instance of abstract class %s” %cls) but now if I create a class G that inherits from F like so: class G(F): pass then I can’t instantiate G either, … Read more
This may be a generic OOP question. I wanted to do a generic comparison between an interface and an abstract class on the basis of their usage. When would one want to use an interface and when would one want to use an abstract class? 25 s 25 I wrote an article about that: Abstract … Read more
I was wondering how to unit test abstract classes, and classes that extend abstract classes. Should I test the abstract class by extending it, stubbing out the abstract methods, and then test all the concrete methods? Then only test the methods I override, and test the abstract methods in the unit tests for objects that … Read more
I’m originally a Java programmer who now works with Objective-C. I’d like to create an abstract class, but that doesn’t appear to be possible in Objective-C. Is this possible? If not, how close to an abstract class can I get in Objective-C? 2Best Answer 21 Typically, Objective-C class are abstract by convention only—if the author … Read more
