Prefer composition over inheritance?
Why prefer composition over inheritance? What trade-offs are there for each approach? When should you choose inheritance over composition?
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How can I create a copy of an object in Python?
To get a fully independent copy of an object you can use the copy.deepcopy() function. For more details about shallow and deep copying please refer to the other answers to this question and the nice explanation in this answer to a related question.
What is difference between functional and imperative programming languages?
Definition: An imperative language uses a sequence of statements to determine how to reach a certain goal. These statements are said to change the state of the program as each one is executed in turn. Examples: Java is an imperative language. For example, a program can be created to add a series of numbers: Each statement changes … Read more
Error at constructor : Expected an identifier?
Your constructor should be defined the following way
What is a “driver class”?
A “Driver class” is often just the class that contains a main. In a real project, you may often have numerous “Driver classes” for testing and whatnot, or you can build a main into any of your objects and select the runnable class through your IDE, or by simply specifying “java classname.”
What is a mixin, and why are they useful?
A mixin is a special kind of multiple inheritance. There are two main situations where mixins are used: You want to provide a lot of optional features for a class. You want to use one particular feature in a lot of different classes. For an example of number one, consider werkzeug’s request and response system. I … Read more
Separating class code into a header and cpp file
The class declaration goes into the header file. It is important that you add the #ifndef include guards. Most compilers now also support #pragma once. Also I have omitted the private, by default C++ class members are private. and the implementation goes in the CPP file:
extends class and implements interface in java
61 extends should go before implements:
What are metaclasses in Python?
A metaclass is the class of a class. A class defines how an instance of the class (i.e. an object) behaves while a metaclass defines how a class behaves. A class is an instance of a metaclass. While in Python you can use arbitrary callables for metaclasses (like Jerub shows), the better approach is to make it … Read more
Difference between abstraction and encapsulation?
What is the precise difference between encapsulation and abstraction?