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To become better at .NET I found it helpful to look into the .Net-Framework itself and how Microsoft implements all the nice things. The last time I used my decompiler to have a look at the implementation of System.String-Class, to research how a String-Object stores its actual string. I was surprised about the largest of the class in self and that I can't clearly identify which part of the class the actual string saves.

Here are two screenshot of the decompiling which shows the start and the end part of the class: enter image description here enter image description here

I suppose that [System.Reflection.DefaultMember("Chars")] (first line in first screenshot) and/or the property public extern char this[int index](middle of second screenshot) the what I am looking for.

Is that the correct and if yes how does it work?

Nathaniel Ford
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Micha
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  • Would be helpful for further questions if upvoter and downvoter leave a comment. Thanks. – Micha Apr 29 '13 at 12:56

1 Answers1

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System.String is a very special type. It's the only type in .NET other than arrays where different instances can have different sizes. (Anything else which "appears" to have different sizes such as List<T> usually depends on an array, or some recursive type like a LinkedList node. The objects themselves are of a fixed size.) The character data is inline within the object itself, along with the length of the string. It's not like a String holds a reference to a char[] or similar.

The CLR has very deep knowledge of System.String, and a lot of it is implemented in native code. Basically, I would recommend against trying to understand the implementation at this point - it's likely to be more confusing than helpful.

The Chars member (the indexer in C#) only fetches a single character from the string. You could follow that to find out more about where the data is stored, but it doesn't perform the actual storage itself.

Jon Skeet
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  • Allthough I agree this sounds more like a comment than an answer to me – Emond Apr 29 '13 at 06:28
  • @ErnodeWeerd: I've added a bit more concrete information about where the actual data lives. – Jon Skeet Apr 29 '13 at 06:30
  • I guess will be good to add also link to the chapter of Jon's book "C# in Depth": [Strings in C# and .NET](http://csharpindepth.com/Articles/General/Strings.aspx) – outcoldman Apr 29 '13 at 06:32
  • Thank Jon for your answer. A little bit surprising (but very interesting) that the things are so complex. – Micha Apr 29 '13 at 12:42