The topic at hand is interning. More specifically, string interning.

“What is string interning?” you ask? Good question. As you may or may not know, strings are immutable reference types. This means that they are read-only and a pointer will refer to the string’s location on the heap. Typically, a new string is created and stored within your application’s memory each time that you assign a string – even if the same string is defined repeatedly. What this means is that you can define the same string N times and have it take up the string’s memory N times. This sucks when dealing with repeating string data.

Something which I feel carries a lot of confusion in the .NET realm is virtual methods. During interviews, I tend to ask candidates about virtual methods: why and when they’d use one, what the purposes is, how a virtual method “works” under the hood, and how it differs from “shadowing”. Surprisingly, in what has probably been over one hundred interviews with senior-ish candidates, I don’t believe that more than one or two of them have answered anything about virtual methods correctly. From this I conclude that the understanding of virtual methods is not strong among the typical developer… And so, let us dive in.

I’m a bit tipsy at the moment, so hopefully this post goes well.

A question that I like to ask while interviewing individuals is: “why would you want to use an interface?” I get a ton of answers that span the supposed gamut of programming; some are good and some are of course terrible, however I’d like to share some input on what I feel is the importance of interfaces.

This is my first post. I hope that it doesn’t suck.

As of .NET 2.0, Microsoft introduced the concept of generics. Generics is a concept that allow you to “template” methods and types such as classes and interfaces in a (generally) type-safe way. Upon compilation, generic type metadata is stored in IL, and JIT’d as you reference the generic method or class with an actual type at runtime. Value types each get their own “copy” of the JIT’d generic code, whereas reference types share a single instance of the code. This is because the generic implementation is identical for reference types – they’re all just pointers.