Click here to Skip to main content
15,867,568 members
Articles / Programming Languages / C#
Tip/Trick

.NET Coding Best Practices

Rate me:
Please Sign up or sign in to vote.
2.58/5 (27 votes)
20 Jan 2010CPOL2 min read 49.4K   10   8
.NET Coding Best Practices - Vinayak's thumb rulesDo not hard code strings/ numerics. Instead of that use constants as shown below.Bad practice int Count; Count = 100; if( Count == 0 ) { // DO something… }Good practice int Count; Count = 100; private...
.NET Coding Best Practices - Vinayak's thumb rules


  1. Do not hard code strings/ numerics. Instead of that use constants as shown below.

    Bad practice

    C#
    int Count;
    Count = 100;
    if(  Count  ==  0 )
    {
     // DO something…
    }
    


    Good practice

    C#
    int Count;
    Count = 100;
    private static const int ZERO  =  0;
    if(  Count  ==  ZERO )
     {
       // DO something…
     }
    


  2. For string comparison - Use String. Empty instead of “”

  3. By default keep the scope of member variables to ‘private’, based on the needs expand the scope either to protected or public or internal.


    1. Other advantage of making the scope private by default is that during XMLSerilaization, by default it will serialize all the public members.


  4. When we have to manipulate the strings inside a loop, use StringBuilder instead of string as shown below.

    Bad practice

    C#
    String  temp = String.Empty;
    for( int I = 0 ; I<= 100; i++)
    {
      Temp += i.ToString();
    }
    


    Good practice

    C#
    StringBuilder sb = new StringBuilder();
    for ( int I = 0 ; I<= 100; i++)
     {
       sb.Append(i.ToString());
      }
    


  5. Prefer Arrays over Collections for simple operations.

  6. Prefer Generic Collections over ArrayList

  7. Prefer Generic Dictionaries over HashTable *.

  8. Prefer StringCollections and StringDictionaries for String manipulations and storage.

  9. Use the appropriate data types.

    For ex: if you want to check for any status, prefer bool rather than int.

    Bad practice

    C#
    int Check = 0;
    if(Check == 0)
     {
       // DO something
      }
    


    Good practice

    C#
    bool Check = false;
    if(!Check)
      {
        // DO something
      }
    


  10. Use ‘as’ operator for type casting and before using that resultant value check for null.

    C#
    class A
     {
     }
    
    class B : A
     {
     }
    
    B objB = new B();
    A objA1  = (A) objB;
    A objA 2 = objB as A;
    
    if( objA2 != null)
    {
     //Do something
    }


  11. For WCF proxy creation, use the using statement

    C#
    using(Cerate the proxy)
     {
       //Do the required operation
      }
    


  12. Follow ‘Acquire late, release early’ rule for expensive resources such as Connection, File etc.

    For ex : if you want to make use of SqlConnection Object for any data operations, create the instance at the method level rather than at the class level.

    C#
    class MyData
     {
         public MyData()
           {
           }
         public List<Customer> GetAllCustomer()
           {
           using(SqlConnection objConnection = new SqlConnection("Connection string"))
             {
               //Do the operation and get the required data..
             }
           }
    }
    


    If you want to create the SqlConnection instance at the class level, ensure that you are implementing the IDisposable for the class and doing the cleanup of SqlConnection instance at the Dispose();

    C#
    class MyData : IDisposable
     {
        SqlConnection objConnection = default(SqlCOnnection);
        public MyData(){
          objConnection = new SqlCOnnection("Connection string");
        }
        public List<Customer> GetAllCustomer(){
          // By using objConnection get the required data
        }
        public void Dispose(){
         // Do the cleanup of SqlCOnnection
         if( objConnection != null ){
            if( objConnection.State == ConnectionState.Open){
           objConnection.Close();
            }
         }
       }
    }
    


  13. If you do not want anybody to extend your class functionalities, make it ‘sealed’ to get the inlining and compile time benefits

  14. Avoid declaring the ‘destructor’ for every class. This will increase the life time of the class which un necessarily makes them long lived

  15. Prefer using Thread Pool over manual threading.

  16. Do not make any calls to a method from the loop.

    For ex :

    Bad practice

    C#
    for( int i = 0; i<= 100; i++)
    {
    	Calculate(i);
    }


    Good practice

    C#
    for( int i = 0; i<= 100; i++)
    {
      //Inline the body of Calculate.
    }


  17. Do not handle exceptions inside a loop, rather handle looping logic inside try/catch

    For ex:

    Bad practice

    C#
    for(int i = 0 ; i<= 100; i++){
       try{
       }
       catch(Exception ex){
          throw ex;
       }
    }


    Good practice

    C#
    try{
      for(int i = 0 ; i<= 100; i++){
      }
    }
    catch(Exception ex){
     throw ex;
    }
    


  18. Do not handle application logic by using Exception.

    For ex :

    Bad practice

    C#
    try{
      int  x,y,z;
      x = 0;
      y = 10;
      z = y/x;
     }
    catch(DevideByZeroException ex){
      throw ex;
    }
    


    Good practice

    C#
    private static const int ZERO  =  0;
    try{
      int x,y,z;
      x = 0;
      y = 10;
      if( x != ZERO){
        z = y/x;
      }
     }
    catch(Exception ex){
     }
    


  19. Prefer for/while loop over foreach

  20. For communication between the layers, prefer Data Transfer objects over DataSet/DataTables.

I hope this will help you all to improve the code quality!!

Happy programming

Regards,
-Vinayak

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Architect MindTree Ltd
India India
Motivated achiever who guides organizations in applying technology to business settings, provides added value, and creates project deliverables in a timely manner. An experienced Technical Consultant, have successfully led large project teams of more than 20 people from requirements gathering to implementation and support using C#, .NET ,ADO.NET, ADO.NET Entity Framework,ASP.NET,ASP.NET MVC, WCF and SQL Server.

Comments and Discussions

 
GeneralImprove the snippet codes Pin
Adaying23-Sep-15 2:08
Adaying23-Sep-15 2:08 
GeneralMy vote of 3 Pin
Chamila Nishantha15-Nov-12 17:39
Chamila Nishantha15-Nov-12 17:39 
GeneralSome good ideas... Pin
Sebastian Br.25-Jan-10 22:05
Sebastian Br.25-Jan-10 22:05 
General[My vote of 2] Comment on the article Pin
jstemper21-Jan-10 6:27
professionaljstemper21-Jan-10 6:27 
General#1, #2, #9, #15, #17, #18, #19 Pin
supercat920-Jan-10 6:05
supercat920-Jan-10 6:05 
GeneralIf these are considered best practices... PinPopular
bhogan22-Dec-09 7:14
bhogan22-Dec-09 7:14 
GeneralMost are good tips... PinPopular
Ron Beyer22-Dec-09 3:44
professionalRon Beyer22-Dec-09 3:44 
GeneralRe: Most are good tips... Pin
kornman0012-Jan-10 5:20
kornman0012-Jan-10 5:20 

General General    News News    Suggestion Suggestion    Question Question    Bug Bug    Answer Answer    Joke Joke    Praise Praise    Rant Rant    Admin Admin   

Use Ctrl+Left/Right to switch messages, Ctrl+Up/Down to switch threads, Ctrl+Shift+Left/Right to switch pages.