Dictionary

Summary When returning objects from a method try to use IList, IDictionary, etc instead of List and Dictionary. This is especially important when the method is inside a class library which you distribute.

Filtering out entries in a dictionary is not too difficult when the key and value are simple. For example if you had - IDictionary oneToFourDictionary = new Dictionary {{ "one", 1 }, { "two", 2 }, { "three", 3 }, { "four", 4 } };