C# Coding Practicies Guide

Introduction

Writing consistent code comprehended by other developers is supposed to follow some coding style and practices, rather than inventing your own ones. These include naming conventions on how you name your variables and functions, code and class layout including tabs, whitespace, brackets placement, etc... Though C# is much easier to develop code when compared to C++ (as VS provides you even automatic indentation and code formatting), there are some quick guidelines you should follow. There are also some great online resources you may use in addition to that article:

• Artistic Style code formatter
• Coding standards

Value and Reference Semantics

Compared to C++, in C# there is inherent value and reference semantics. As there are no pointers in safe code and everything is accessed with '.', there are value and reference types:

• Value types - struct, enum, integrals, char, float, double, decimal
• Reference types - class, string, interface, arrays, delegates

So having initialization of a value or reference type, you get different results:

SomeStruct ss = new SomeStruct();
SomeClass sc = new SomeClass();
SomeStruct ss1 = ss;  //you will have new ss1 object created
SomeClass sc1 = sc;   //you get sc reference in sc1!!!

Spaces, Braces, Tabs, Code Layout

No need to worry about these, VS will do all formatting for you automatically like the one snippet below, so you are prevented from incorrectly layouting your code. Very nice feature for C#, hope the same tool will be available for C++ language.

public int SaveDictionary(String fileName)
{
        try
        {
                using (StreamWriter sw = new StreamWriter(fileName))
                {
                        foreach (String word in this.stats.Keys)
                        {
                                sw.WriteLine(word);
                                List<WordFreqPair> wfpList = this.stats[word];
                                for (int i = 0; i < wfpList.Count; i++)
                                        sw.WriteLine(String.Format("    {0,-25} {1}", 
					wfpList[i].Word, wfpList[i].Prob));
                                sw.WriteLine("");
                        }                        
                }
                return 0;
        }
        catch (Exception e)
        {
                Trace.WriteLine(String.Format("TextStatistics.SaveDictionary({0}) 
			raised exception {1}", fileName, e.Message));
                this.error = String.Format("TextStatistics.SaveDictionary({0}) 
			raised exception {1}", fileName, e.Message);
                return -1;
        }
}

Naming Conventions

.NET standards do not recommend using Hungarian prefixes, so avoid them. To refer to member field inside class member function, use this word this.memberVariable. You use lower case for variables and function parameters, all the rest go with capitals:

SomeClass { ... };
SomeEnum { Item1, Item2, ... };
SomeProperty { get; set }
double someVariable;
int someFunctionParameter;
const char SomeConstantVariable;
static readonly SomeReadOnlyStaticVariable;
Exception SomeNameException;
Attribute SomeNameAttribute;
Button cancelButton;
TextBox nameTextBox;
PictureBox namePictureBox;

Class Layout

It is recommended to declare class internals in that order:

• Fields
• Constructors
• Nested enums, structs, classes
• Properties
• Methods

Miscellaneous

One class per source file (SomeName class should be declared in somename.cs file).

Private members are private by default in class, avoid explicit private.

For a single statement get/set property use that construction:

public int Foo
{
        get { return this.foo; }
        set { this.foo = value; }
}

Use {} for if, else, for, while even if single lined.

if (someVar == true)
{
        foo++;
}

Use @ instead of escape sequencies in strings - @"c:\somepath\file.txt"

Use override instead of new:

class SomeParent
{
        //...
        public int DoWork();
        //...
}

class SomeOverride
{
        //...
        public override int DoWork();
        //...
}

Initialize string to String.Empty rather than assigning it "".

Use StringBuilder for composing complex strings rather than using string class operators.

Document if the method returns copy of reference type.

Do not compare to true or false use if(condition).

Provide private constructor if only static fields are in the class or declare static class.

Const objects in class are static by default.

Struct may have constructor with parameters only.

Consider documenting your code so you will not be trying to recall what the method is supposed to do after some days have gone.

/// <summary>
/// Save trimmed text
/// </summary>
/// <param name="fileName">Trimmed text file name</param>
/// <returns>zero upon success</returns>
public int SaveText(String fileName)
{
//...
}

History

• 20^th June, 2008: Initial post