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Lesson 17 - Indexers, Equals, constants, enumerated types and flags

In the previous exercise, Solved tasks for OOP in C# .NET lessons 14-16, we've practiced our knowledge from previous lessons.

In the previous lesson, Solved tasks for OOP in C# .NET lessons 14-16, we went over abstract classes and learned how to overload operators in C# .NET. The last 3 lessons were very practical, as in lots of doing and getting right into sample programs. This time around we're going to get back into theoretical concepts for a little bit.


Similarly, as we could overload an operator, in our own class, we can overload the indexer as well. We know indexers very well from collections, we use them as brackets [] and they allow us to work with classes as if they were collections. We can index both by numbers or strings. Let's make a quick little class:

class CustomCollection
        private List<int> internalCollection = new List<int>(new int[] {1, 2, 3, 4, 5});

The class contains an internal collection of 5 numbers, where we will now implement a custom indexer. In .NET, we implement indexers as properties. They are declared like this:


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This tutorial is about indexer overloading, the Equals method as well as the == operator, constants, enumerated types (enums) and flags.

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Article has been written for you by David Capka
The author is a programmer, who likes web technologies and being the lead/chief article writer at He shares his knowledge with the community and is always looking to improve. He believes that anyone can do what they set their mind to.
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