Generate year into connection string C#

private const string strCon1 = "Data Source=.\\SQLEXPRESS;Initial Catalog=BSS {0};Integrated Security=True";

. . .

string strCon = string.Format(strCon1, DateTime.Now.Year);

Using a placeholder ({0}) with string format gives you precise control. 

Or you could use:

 

private static readonly string strCon1 = $"Data Source=.\\SQLEXPRESS;Initial Catalog=BSS {DateTime.Now.Year};Integrated Security=True";

Declare static readonly year; 

private readonly static string _year = DateTime.Now.Year.ToString();

and use _year in your connection string.

Hi Goran Bibic,

• const value will not change during the lifetime of the program.
• readonly assigned a value at the class scope or in a constructor only

Hence, instead of const you can use readonly in following way:

public class ConnectionString
{
    const string strCon1 = "Data Source=.\\SQLEXPRESS;Initial Catalog=BSS 2022;Integrated Security=True";
    readonly string strCon2 = "Data Source=.\\SQLEXPRESS;Initial Catalog=BSS 2020;Integrated Security=True";

    public ConnectionString()
    {
        //strCon1 = strCon1.Replace("2022", "2023");//compile error
        string year = DateTime.Now.Year.ToString();
        strCon2 = strCon2.Replace("2020", year);
    }

    public string getConnectionString
    {
        get { return strCon2; }
    }
}

Use it in another class:

ConnectionString objConnectionString = new ConnectionString();
Console.WriteLine(objConnectionString.getConnectionString);

For more details:

• How to use const, readonly, and static in C#
  • https://www.infoworld.com/article/3546242/how-to-use-const-readonly-and-static-in-csharp.html

Hope this will help you!