IsError Question

[Ark68]

I am trying to determine if a user inputted value (txt_freq) is a number or not using this code:

txt_freq = "dsadfdfs"
If IsError(txt_freq * 1) Then
   freqval = False
   MsgBox "Invalid frequency (Non numeric)"
    Exit Do
End If

The line is throwing a "Type mismatch" error, rightly so as a mathematical function is being applied to a alphabetical variable. I'm assuming this is not how to catch this error?

 

[Scott Huish]

I would use Isnumeric

txt_freq = "dsadfdfs"
If Isnumeric(txt_freq)=false Then
   freqval = False
   MsgBox "Invalid frequency (Non numeric)"
    Exit Do
End If

Although if you are using an InputBox, you can force a numeric entry.

 

[Peter_SSs]

I am trying to determine if a user inputted value (txt_freq) is a number or not using this code:

I would say that it depends on just what sort of "number" you are expecting, how rigorous you want/need to be and how weird the values entered by the user might be.
Mentioning those things because IsNumeric has some funny characteristics. For example if any of these values are used as txt_freq in the above code then no message box will appear yet I expect they are not the sort of values you would want to be entered & accepted.
"3,5,6$"
"4e4"
"23,,,,,.3"

There are plenty more such values that can be found.

 

[Scott Huish]

Hmmm. Learn something new everyday.


The worksheet function seems to work as expected.

txt_freq = "4e4"
If Application.WorksheetFunction.IsNumber(txt_freq + 1) Then
   freqval = False
   MsgBox "Invalid frequency (Non numeric)"
    Exit Do
End If

 

[Ark68]

Hi Scott and Peter, thank you for your contributions.
Scott's suggestion will work, thank you. However, Peter, you are correct ... although highly unlikely, if it can happen it will eventually, that someone enters such a value that the IsNumeric function won't catch. In my full code, I have a half dozen other error traps that ensure that a properly formatted number is entered. My full code as I've been playing with can be found here if curious.

If indeed the Isnumeric fuction identifies the entry as infact being a number, is it a true number? Can I use it as is incalculations? Or would I need to convert the value to a number first? (I'm of the understanding that entries into an inputbox are strings).

 

[Peter_SSs]

The worksheet function seems to work as expected.

txt_freq = "4e4"
If Application.WorksheetFunction.IsNumber(txt_freq + 1) Then
   freqval = False
   MsgBox "Invalid frequency (Non numeric)"
    Exit Do
End If

Surely that would suffer the same "Type mismatch" error as reported in the OP if that same txt_freq input was used?