option explicit

[mikieprojects48]

I'm new to vba and going through the Dummies for VBA book now, one of the example exercises is for CUBEROOT.

Sub CubeRoot()
Num = InputBox("Enter a positive number")
MsgBox Num ^ (1 / 3) & " is the cube root. "
The only way that I can get the macro to work is by removing the Option Explicit from the text window. I read that option explicit protects the code and if you put the letters dim in front of the lines the macro will work not able to get the right combination any help would be appreciated
mikie48

 

[njimack]

Dim Num as Integer
Num = InputBox("Enter a positive number")

 

[pedie]

Option Explicit forces us user to declare variable.
when 'm not sure I just decalare it for exmapel as as
dim num

[/FONT]
[FONT=Courier New]Option Explicit[/FONT]
[FONT=Courier New]Sub CubeRoot()
Dim Num As Integer
Num = InputBox("Enter a positive number")
MsgBox Num ^ (1 / 3) & " is the cube root. "
End Sub
[/FONT]
[FONT=Courier New]

 

[Rick Rothstein]

Option Explicit is a good thing and should not be disabled (IMHO). Having it enabled will allow VB to alert you when you are using a variable or constant that you did not declare in some way (usually using a Dim statement, but Private, Public, Static, Const, etc. are other ways to declare things). In your posted case, the code is using a Num variable that was not declared, so VB is warning you of that fact. Change your code fragment to this...

Sub CubeRoot()
Dim Num As Double
Num = InputBox("Enter a positive number")
MsgBox Num ^ (1 / 3) & " is the cube root. "

and your code will work fine. Note that I guessed at Double because I assumed floating point values were intended, but we could have used Integer or Long if whole numbers were what was expected.

Oh, and the reason using Option Explicit is a good idea... it will save you lots of debugging time when you create a variable named, say, firstline or Var01 and accidentally type them later on in your code as first1ine or VarO1. If you declare firstline and Var01 using Dim statements, and you have Option Explicit enabled, then you will be alerted to the mistyped variable names by VB. Without Option Explicit, it is possible your code will not crash, but rather continue on by calculation incorrect values based on those mistyped variable names. As I said, Option Explicit is a good thing to use (it save my butt many times across the years when I was still actively programming). By the way, the difference between the intended variable names and the mistyped ones may be more obvious in the font used here in this forum, but it will be harder to spot in the font used in the VB editor.

 

[mikieprojects48]

Thank you

 

[mikieprojects48]

Thank you I never really knew how powerful excel is

 

[mikieprojects48]

Thanks for the help