Empty list of string

Question

I'm writting a class that simplifies my coding when using QBFC (quickbooks integration).

I am going to have many functions with optional paramaters of list of strings. The problem I have is that I am unsure how to specify the default value. I want to pass an empty list to code if a list is not specified. How does one do this. I'm sure this is a simple answer, but I'm coming up with a blank on every search I've done.

Thanks,
Cam

Cam · Answer

Thanks for the reply actually I just found the answer. I really wasn't asking about the optional keyword I couldn't figgure out how to set an empty list as the default for the paramater. Here is the answer from the msdn (I wasn't reading very well): defaultvalue Required for Optional parameters. Any constant or constant expression that evaluates to the data type of the parameter. If the type is Object  or a class interface array or structure the default value can only be Nothing . So in my code I simply listed  Optional ByVal ListIDList As List( Of String ) = Nothing in my parameter list. I knew it was simple I was simply just missing the answer right in front of my face. Thanks for the QUICK response though.

Mahesh Chand · Answer

If you are using VB.NET you can use keyword optional in front of a parameter. Every optional argument must declare a default value and there is no need of IsMissing function. For example: Sub MyMethod( Optional ByVal i As Integer = 3) --------------------------------------------------- C# however does not support optional parameters. You will have to overload your methods. For example you may have a method with three overloaded forms something like this: public string AddParams(string str1); public string AddParams(string str1 string str2); public string AddParams(string str1 string str2 string str3); Other approach is you MUST passs a null or emptry string and in your method check the value of the parameter and if its null or empty depending on your approach you can ignore that parameter.