Chapter 6, The .NET Collections

1. System.Collections, System.Collections.Generic, System.Collections.Concurrent, and System.Collections.Specialized.
2. Big O notation is used to determine algorithmic efficiency.
3. Algorithmic efficiency determines how time scales with respect to input.
4. Benchmarking showed that using IList<T> was faster than using List<T>, and so using IList<T> is preferred over using List<T>.
5. You can use either. What you choose depends upon your performance requirements and what you are trying to achieve. There are trade-offs between using collections and arrays. Understanding these trade-offs will help you choose which option you should apply to your code.
6. Indexers enable objects in classes to be accessed in the same way as you access items in an array.
7. IEnumerator<T> is faster at iterating through in-memory collections than IEnumerable<T>.
8. In terms of memory and speed performance, querying the database...