FOR Behaves Differently in Visual Basic than in XLM Macro (111725)
The information in this article applies to:
- Microsoft Excel 97 for Windows
- Microsoft Excel 98 Macintosh Edition
This article was previously published under Q111725 SUMMARY
In the versions of Microsoft Visual Basic for Applications that ship with
Microsoft Excel versions 5.0 and later, FOR loops behave differently than
they do in the Microsoft Excel version 4.0 macro language.
The respective macro commands are as follows:
Visual Basic
For counter = startValue To endValue
Next counter
Microsoft Excel Version 4.0 Macro Commands
=FOR("counter",startValue,endValue)
=NEXT()
MORE INFORMATIONMicrosoft provides programming examples for illustration only, without warranty either expressed or implied. This includes, but is not limited to, the implied warranties of merchantability or fitness for a particular purpose. This article assumes that you are familiar with the programming language that is being demonstrated and with the tools that are used to create and to debug procedures. Microsoft support engineers can help explain the functionality of a particular procedure, but they will not modify these examples to provide added functionality or construct procedures to meet your specific requirements.
In Visual Basic, the number of iterations for the loop cannot be changed
by changing the value of the variable used to set the ending value for
the loop while the loop is in progress (this behavior is standard for
most programming languages that use FOR loops). However, you can change
the value of the variable in a Microsoft Excel version 4.0 style macro
using the equivalent functions, FOR() and NEXT().
Microsoft Excel Version 4.0 Macro Example
In the following Excel 4.0 style macro, the loop is originally set to run
ten times. However, it will only run 5 times because the ending value is
modified during the loop. To test this behavior, enter the following on a
Microsoft Excel 4.0 macro sheet:
A1: y=10
A2: =FOR("x",1,y)
A3: y=5
A4: =NEXT()
A5: =ALERT(x)
A6: =RETURN()
To run the macro, select cell A1, click Macro on the Tools menu, and then
click Run.
The ALERT() statement in A5 will display the value 6, which means that the
loop only ran 5 times, as opposed to the 10 times that the original value
of "y" was set for.
Sample Visual Basic Procedure
In the following Visual Basic macro, the loop is originally set to run 10
times and it will run 10 times, even though the macro changes the value of
the variable that is used to set the ending value of the loop.
To test this macro:
- Enter the following in a new Visual Basic module:
Sub MyLoop()
Dim x, y As Integer
y = 10
For x = 1 To y
y = 5
Next x
MsgBox x
End Sub
- Position the insertion point in the line that reads "Sub MyLoop()" and
either press F5 or click Start on the Run menu.
The MsgBox statement in the above macro displays the value 11, which means
the loop ran through 10 times, even though we changed the value of the
variable used to set the ending value of the loop.
REFERENCES
"Visual Basic User's Guide," version 5.0, pages 143-147
For more information about FOR, choose Contents from the Help menu, select
Programming With Visual Basic, and then choose the Search button in Help
and type the following:
Modification Type: | Minor | Last Reviewed: | 10/10/2006 |
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Keywords: | kbdtacode kbhowto kbProgramming KB111725 |
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