Which scenario best exemplifies the Dependency Inversion Principle?
A 'Logger' class writes logs directly to a file.
A 'DataProcessor' class depends on an 'IDataSource' interface, not a specific database implementation.
A 'LightSwitch' class is directly dependent on a 'LightBulb' class.
A 'Car' class directly instantiates and uses an 'Engine' class.
What is the primary purpose of the Open/Closed Principle?
To allow extending functionality without altering existing code
To prevent modification of existing code
To enforce the use of abstract classes
To ensure all methods are open for modification
In the context of the Open/Closed Principle, what does 'open for extension' mean?
Code should be heavily commented to explain every detail.
The source code of a class should always be accessible for any developer to modify.
A class's behavior should be modifiable through inheritance or polymorphism.
All classes should be loosely coupled and easily replaceable.
What is a potential drawback of NOT following SRP?
Classes become more reusable and easier to understand.
Changes in one part of the code are less likely to affect other parts.
Classes become more focused and have a clearer purpose.
The codebase becomes more difficult to maintain and prone to bugs.
In the context of ISP, why are 'role interfaces' considered good practice?
They are specific to how a particular client uses a class, regardless of its primary responsibility.
They violate the Single Responsibility Principle.
They define a broad set of methods used by many unrelated classes.
They are only applicable to abstract classes, not interfaces.
In the context of DIP, what are abstractions typically represented by?
Concrete classes
Database connections
Interfaces or abstract classes
User interface components
How can you identify potential violations of the Liskov Substitution Principle in your code?
By only using abstract classes and interfaces.
By avoiding inheritance altogether and favoring composition.
By looking for instances where a subclass throws an exception not declared in the superclass or introduces behavior that breaks the superclass's contract.
By ensuring all methods in subclasses are static.
In the context of LSP, what is meant by 'substitutability'?
The capability to use a subclass object wherever a superclass object is expected without causing issues.
The practice of always using abstract classes instead of concrete classes.
The ability to change the behavior of a superclass by modifying its subclass.
The idea that all methods in a subclass should be static.
Why might strictly adhering to the Open/Closed Principle in every single part of a codebase be impractical?
It simplifies the design too much.
It violates other SOLID principles.
It can lead to over-engineering and unnecessary complexity in some cases.
It makes the codebase less secure.
How does the Open/Closed Principle contribute to creating maintainable code?
It eliminates the need for testing.
It makes the codebase smaller.
It allows for easier addition of new features without impacting existing ones.
It reduces the need for code documentation.