C# Field Naming Guidelines?

Question

I am going to be working on a bit of C# code on my own but I want to make sure that I follow the most widely accepted naming conventions in case I want to bring on other developers, release my code, or sell my code. Right now I am following the naming convention that Microsoft has set as they seem to be the most widely accepted. The one thing they don't mention though is naming for private fields. For the most part I have seen them named in camelCase like protected fields however that present me with an issue as parameter names should be in camelCase. Take the following constructor for example:

public GameItem(string baseName, string prefixName, string suffixName) {     //initialize code } 

Now if I use camelCase for the private fields too there is a naming conflict unless I use "this" in order to access the class fields (which I think is against most standards not to mention means more typing). One solution is to give the parameter a different name but that does not make logical sense to give the same data 2 different names. The only other solution that I know of that was common in C++ coding is giving private members an underscore at the beginning (_camelCase). Is that solution commonly accepted with C# coding? Is there another solution to this problem (like only using properties (which use PascalCase) to access fields, even in the class itself)?

Answer 1

_camelCase for fields is common from what I've seen (it's what we use at our place and Microsoft prefer for the .NET Runtime).

My personal justification for using this standard is that is is easier to type _ to identify a private field than this.

For example:

void Foo(String a, String b) {     _a = a;     _b = b; } 

Versus

void Foo(String a, String b) {     this.a = a;     this.b = b; } 

I find the first much easier to type and it prevents me from ever accidentally assigning to the parameter called a instead of this.a. This is reinforced by a Code Analysis Maintainability Rule that states:

• CA1500 Variable names should not match field names.

My other reason, is that this. is optional (Visual Studio / Code prompts you to remove them) if it doesn't collide with a local variable or parameter name, making knowing which variable you are using harder. If you have an _ at the start of all private fields, then you always know which is a field and which is has local scope.

Answer 2

Follow the Microsoft Naming Guidelines. The guidelines for field usage indicate that it should be camelCase and not be prefixed. Note that the general rule is no prefix; the specific rule is not to prefix to distinguish between static and non-static fields.

Do not apply a prefix to field names or static field names. Specifically, do not apply a prefix to a field name to distinguish between static and nonstatic fields. For example, applying a g_ or s_ prefix is incorrect.

and (from General Naming Conventions)

Do not use underscores, hyphens, or any other nonalphanumeric characters.

EDIT: I will note that the docs are not specific with regard to private fields but indicate that protected fields should be camelCase only. I suppose you could infer from this that any convention for private fields is acceptable. Certainly public static fields differ from protected (they are capitalized). My personal opinion is that protected/private are not sufficiently different in scope to warrant a difference in naming convention, especially as all you seem to want to do is differentiate them from parameters. That is, if you follow the guidelines for protected fields, you'd have to treat them differently in this respect than private fields in order to distinguish them from parameters. I use this when referring to class members within the class to make the distinction clear.

EDIT 2

I've adopted the convention used at my current job, which is to prefix private instance variables with an underscore and generally only expose protected instance variables as properties using PascalCase (typically autoproperties). It wasn't my personal preference but it's one that I've become comfortable with and probably will follow until something better comes along.