Design Patterns & Architecture Flashcards

Which pattern ensures a class has only one instance and provides a global access point?

Answer: Singleton

The Singleton pattern restricts instantiation of a class to one object and provides a static method to access it.

In the Composite pattern, what role does the 'Leaf' class play?

Answer: It is a primitive object with no children

A Leaf represents a basic element with no children, implementing the component interface directly.

Which design pattern converts the interface of a class into another interface that clients expect?

Answer: Adapter

The Adapter pattern wraps an existing class to make its interface compatible with another interface.

What problem does the Chain of Responsibility pattern solve?

Answer: Passing a request along a chain of handlers without knowing which will handle it

Chain of Responsibility lets handlers decide whether to process a request or pass it to the next handler in the chain.

In C++, the 'std::function' combined with lambdas is most closely associated with which pattern?

Answer: Strategy

The Strategy pattern defines a family of algorithms that can be swapped at runtime, matching how std::function holds interchangeable callables.

Which pattern separates an abstraction from its implementation so both can vary independently?

Answer: Bridge

The Bridge pattern decouples abstraction and implementation by placing them in separate class hierarchies linked by composition.

The Template Method pattern relies primarily on which C++ mechanism?

Answer: Virtual functions and inheritance

Template Method defines a skeleton algorithm in a base class using virtual functions that subclasses override to fill in steps.