FunctionReturnValueNotUsed

Warns when a user function's return value is never used, at any of its call sites.


Inspection type: CodeQualityIssues

Default severity: Warning

Reasoning

A 'Function' procedure normally means its return value to be captured and consumed by the calling code. It's possible that not all call sites need the return value, but if the value is systematically discarded then this means the function is side-effecting, and thus should probably be a 'Sub' procedure instead

Quick-Fixes

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.
  • ConvertToProcedure: Adjusts a Function procedure to be a Sub procedure. This operation may result in broken code.

Examples

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 trigger this inspection:

Module1

Public Sub DoSomething()
    GetFoo ' return value is not captured
End Sub
Private Function GetFoo() As Long
    GetFoo = 42
End Function

Back to list

The content of this page was generated from xml/comments in the source code compiled into Rubberduck.CodeAnalysis.xml. Edit this page