VBA Argument Not Optional: Understanding and Resolving the Error
Let’s see how to fix the VBA Argument Not Optional error in Excel VBA.
Why I see “Argument Not Optional” Error?
To understand this error better, let’s take a look at a VBA example:
Sub MySub(arg1 As Integer, arg2 As String)
‘ My code VBA to put here
End Sub
Sub CallerSub()
MySub 42
End Sub
In this code snippet, the MySub subroutine expects two arguments (arg1 and arg2), but when we call it in CallerSub, we provide only one argument (42). This will trigger the “Argument Not Optional” error.
How to Resolve the “Argument Not Optional” Error
Resolving this error involves identifying which procedure or function is causing the issue, understanding what arguments it expects, and ensuring that you provide the correct number of arguments with the right data types. Here’s a step-by-step guide to resolving the error:
Check the Procedure or Function Signature
Start by examining the procedure or function that’s causing the error. Look at its signature to determine how many arguments it expects and what their data types should be. Make sure you understand the purpose of each argument.
Verify the Number of Arguments
Ensure that you provide the correct number of arguments when calling the procedure or function. If the function expects two arguments, provide two, and ensure they are in the correct order.
Validate Data Types
Check that the data types of the arguments you’re passing match the data types expected by the procedure or function. VBA is strict about data types, so any mismatch will result in the error.
Use Named Arguments
For clarity and accuracy, consider using named arguments when calling procedures or functions. This way, you can explicitly specify which argument corresponds to each parameter in the function.
Example using named arguments:
Sub CallerSub()
MySub arg1:=42, arg2:=”Hello”
End Sub
Utilize Debugging Tools
VBA provides debugging tools that can help you pinpoint the source of the error. Utilize features like the Immediate window and the Locals window to inspect variable values during runtime, which can be immensely helpful in identifying issues.
By following these steps, you can effectively resolve the “Argument Not Optional” error in your Excel VBA code, making your coding experience smoother and more error-free.
