The entry for each function includes basic syntax information, with the details of parameters and return values. This is followed by a functional description and usage information (in the "Description" and "Usage at a Glance" sections). Many function entries also include source code examples.
Each VB function is, in fact, a method, since it is a member of a particular class in the Microsoft.VisualBasic (or other) namespace. Each entry identifies the class in which the function appears.
Visual Basic supports both named and positional arguments for most functions , procedures, and methods. Functions, procedures, or methods that accept parameter arrays as arguments don't accept named arguments if the ParamArray parameter is present. Some functions are actually resolved at compile time (the data-conversion functions fall into this category) and do not accept named arguments. To use named arguments, consider the syntax of the Mid function, which has two required arguments and one optional argument.
Mid(str As String, start As Long[, length As Long])
Using positional arguments, you might call the function as follows:
smallPart = Mid(wholeString, 12, 10)
The same function call using named arguments might appear as follows:
smallPart = Mid(start:=12, str:=wholeString, length:=10)
Since most functions accept named arguments, the entries in this chapter only indicate when a function or procedure does not support named arguments.
The "Version Differences" section found in some entries documents changes in usage for the entry between the different versions of Visual Basic, including Visual Basic 6.0, Visual Basic .NET 2002, Visual Basic .NET 2003, and Visual Basic 2005.