C#/WPF面试题 (Epan, Citi)

当然面试问题不可能这么少，我只是把我觉得有意义和我当时答的不好拿出来

Epan面试：

1.简述IDisposable pattern，how it works?

2. Easiest way to convert 5 to 101 which is binary format?  

answer: can use >> operator

3. C# collection complexity performance? 

answer: There is a really good website to explain http://geekswithblogs.net/BlackRabbitCoder/archive/2011/06/16/c.net-fundamentals-choosing-the-right-collection-class.aspx

4. Expression tree. 

5. Volatile. When and how to use it?

Citi面试：

1. Reference type and value type. Difference? Tell more. string type is reference type? why?

Answer: http://www.albahari.com/valuevsreftypes.aspx

2.  immutable and mutable difference? why immutable?

3. What is Lambda expression?

有时候其实经常用，可如果不好好看看一些概念的具体定义的话，面试的时候很吃亏的

4. What is Delegate? definition?

5. int ? int32 ? int64 ? relationship?

6. Object class all the method inside? why we need equals and referenceequals? why we need gethashcode?

7. Reflection definition?

8. Assembly contains? 

answer: metadata, resource, IL

9. .Net Garbage collection

10. What is thread safe? how to make it thread safe?

11. How to implement an notification service using WCF?

asnwer: duplex