Design Pattern Interview Questions

1. Singleton object? How can you achieve effective thread safety?
2. Single ton use cases? How exactly effective single ton creates?
3. How volatile is used in singleton ? where exactly it is needed?
4. What is Object design pattern and when it is required?
5. What is Abstract factory design pattern and how it is helpful?.
6. What is Proxy design pattern and what is the use?
7. Where we use Factory design pattern?
8. What is Factory design pattern?