Section 10: Miscellaneous / Advanced C# (96–100)

96. Difference between ref and out parameters?

• ref: variable must be initialized before passing
• out: variable does not need initialization; must be assigned inside method

97. What is the difference between override and new keyword?

• override: overrides base class virtual method
• new: hides base class method

98. What is memory management in C#?
Managed by CLR via garbage collection; developers don’t manually free memory.

99. What are extension methods?
Static methods that extend existing types without modifying their code.

Example:

public static bool IsEven(this int number) => number % 2 == 0;

100. What is async streams in C#?
Introduced in C# 8.0: allows asynchronous iteration over streams of data using await foreach.

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✅ Summary / Notes for Interview Prep:

• Cover basics, OOP, collections, LINQ thoroughly — 50% of questions are likely from here.
• Be ready to write code snippets for async, LINQ, and collections.
• Be familiar with .NET Core deployment, DI, design patterns, and exception handling.
• Be confident explaining differences (IEnumerable vs IQueryable, ref vs out, abstract vs interface).
• Know real-world applications, e.g., “How would you design a REST API?” or “How would you handle concurrency in a web app?”