5.3.1.5 Parameter Lists

Note

This section describes the implementation of MS-VBAL §5.3.1.5 Parameter Lists.

Syntax

A declared parameter is a VBParameterSymbol; a trailing ParamArray parameter is a ParamArrayParameterSymbol.

The parameter list of a Property Let or Property Set follows this MS-VBAL §5.3.1.5 rule:

property-parameters = "(" [parameter-list ","] value-param ")"

Static Semantics

In the property-parameters rule, value-param is never bracketed, so it is always mandatory, whether or not there are index parameters. A Property Let or Property Set with no parameters has no value parameter to receive what is being assigned, and is reported as VBC09321. See also RD-VBAL §5.3.1.7 Property Declarations.

👉 UDT values must be passed by reference (ByRef). See RD-VBAL §2.5.2.1.3 User-Defined Type (UDT) Values.

Optional parameters

VBParameterSymbol.DefaultValue holds an Optional parameter's default value.

Declaration	`VBParameterSymbol.DefaultValue`
`Optional` with an `= ...` default-value clause	The default value, pre-computed.
`Optional` with no `= ...` default-value clause	`null`

When an Optional parameter has no argument mapped to it, the invocation uses VBParameterSymbol.DefaultValue directly. When DefaultValue is null, it falls back to the parameter's declared type's default value. See RD-VBAL §5.3.1.11 Procedure Invocation Argument Processing.

ParamArray parameters

How the arguments passed to a ParamArray parameter are collected is described in RD-VBAL §5.3.1.11 Procedure Invocation Argument Processing.