Highlights implicit ByRef modifiers in user code.

Inspection type: CodeQualityIssues

Default severity: Hint


VBA parameters are implicitly ByRef, which differs from modern VB (VB.NET) and most other programming languages which are implicitly ByVal. So, explicitly identifing VBA parameter mechanisms (the ByRef and ByVal modifiers) can help surface potentially unexpected language results. The inspection does not flag an implicit parameter mechanism for the last parameter of Property mutators (Let or Set). VBA applies a ByVal parameter mechanism to the last parameter in the absence (or presence!) of a modifier. Exception: UserDefinedType parameters must always be passed as ByRef


The following quick-fixes are available for this inspection:

  • IgnoreOnce: Adds an '@Ignore annotation to ignore a specific inspection result. Applicable to all inspections whose results can be annotated in a module.
  • IgnoreInModule: Adds an '@IgnoreModule annotation to ignore a inspection results for a specific inspection inside a whole module. Applicable to all inspections whose results can be annotated in a module.
  • SpecifyExplicitByRefModifier: Introduces an explicit 'ByRef' modifier for a parameter that is implicitly passed by reference.


Each example is a self-contained MCVE showing the feature in a single specific scenario.

Standard Module
Named Module1 by default, these are general-purpose standard procedural modules.
Class Module
Named Class1 by default, these modules define the default interface for an object of that type.
Predeclared Class
A class module with its VB_PredeclaredId attribute set to True (with or without a @PredeclaredId annotation).
Interface Module
Abstract interfaces are class modules (with or without an @Interface annotation) whose default interface is not a class type intended to be instantiated.
UserForm Module
A predeclared class with a design-time visual designer using the MSForms UI framework.
Document Module
Owned by the host application, these class modules belong to the host document and may handle various events fired by the host application.

The following code should NOT trigger this inspection:


Private theLength As Long
Public Property Let Length(newLength As Long)
    theLength = newLength
End Sub

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