C#

public class my
       {
           public int num = 0;
           public string s = "";
           public my()
           {
               this.num = 90;
           }
           public my(string n):this()//Calls the parameterless contructor
           {
               this.s = n;
           }

       }

public my(string n)
    :this()
{
    // empty constructor called above!
    this.s = n;
}

public class MyClass
{
    /* Declaring constants here makes it easier if you need to change the
     * defaults later as it will cascade to all the constructors */
    private const int DefaultNumericValue = 90;
    private const string DefaultStringValue = "";

    // Use properties rather than public fields.
    public int NumericValue
    {
        get;
        // If you want it publicly settable, remove the private modifier
        private set;
    }
    public string StringValue
    {
        get;
        private set;
    }

    public MyClass()
        : this(DefaultNumericValue, DefaultStringValue)
    { }
    public MyClass(int numericValue)
        : this(numericValue, DefaultStringValue)
    { }
    public MyClass(string stringValue)
        : this(DefaultNumericValue, stringValue)
    { }
    /* This constructor is called by EVERY other constructor,
     * this helps to make your code more maintainable */
    public MyClass(int numericValue, string stringValue)
    {
        NumericValue = numericValue;
        StringValue = stringValue;
    }
}

public static class Constants
{
    public const int MAXPARAMETERENGTH = 1024;
    public const int SIZEOFCOMMAND = 8;
}

[StructLayout(LayoutKind.Sequential)]
public struct MESSAGE
{
    [MarshalAs(UnmanagedType.ByValArray, SizeConst = Constants.SIZEOFCOMMAND, ArraySubType = UnmanagedType.U1)]
    public byte[] cCommand;
    [MarshalAsAttribute(UnmanagedType.ByValTStr, SizeConst = Constants.MAXPARAMETERENGTH)]
    public string sParameter;
}