Pattern Design Basic Design Pattern 2

Question 1

Which design pattern ensures only one instance of a class is created throughout an application's lifetime?

Accepted Answer

Singleton

Answer

The Singleton pattern restricts instantiation of a class to a single object, providing a global access point to it.

Question 2

What is the primary purpose of the Adapter pattern?

Accepted Answer

Convert an interface into another that clients expect

Answer

The Adapter pattern acts as a bridge between two incompatible interfaces, enabling them to work together without modifying existing code.

Question 3

In which design pattern category does the Iterator pattern belong?

Accepted Answer

Behavioral

Answer

The Iterator pattern is behavioral because it defines how objects communicate and interact, specifically how to traverse a collection.

Question 4

The Composite pattern is best suited for representing which type of structure?

Accepted Answer

A part-whole hierarchy

Answer

The Composite pattern lets clients treat individual objects and compositions uniformly, making it ideal for tree-like part-whole hierarchies.

Question 5

Which pattern defines a skeleton of an algorithm in a base class, deferring some steps to subclasses?

Accepted Answer

Template Method

Answer

The Template Method pattern defines an algorithm's structure in a superclass while allowing subclasses to override specific steps without changing the overall structure.

Pattern Design Practice Test

Pattern Design Practice Test

Pattern Design Basic Design Pattern 2