XL: How to Create a List of Unique Random Integers Between Two Given Values

• Microsoft Excel 98 Macintosh Edition
• Microsoft Excel for Windows 95, version 7.0
• Microsoft Excel for Windows NT, version 5.0
• Microsoft Excel for Windows, versions 5.0, 5.0c
• Microsoft Excel for the Macintosh, versions 5.0, 5.0a

SUMMARY

In Microsoft Excel, you can write a macro to create a list of unique random integers between two numbers.

MORE INFORMATION

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1. Type the following code in a module sheet:

   
         Option Explicit
   
         Sub Unique_Numbers()
   
            Dim x As Long, y As Long, z As Long, tempnum As Long
            Dim flag As Boolean
            Dim i As Integer
            Dim foundCell As Range
   
            Application.ScreenUpdating = False
   
            x = Application.InputBox("Enter starting Random Number" _
               , "Random Number Generation", 1, , , , , 1)
            y = Application.InputBox("Enter ending Random Number" _
               , "Random Number Generation", 1000, , , , , 1)
            z = Application.InputBox("How many random numbers would" _
               & "you like to generate (<15000)?" _
                   , "Random Number Generation", 100, , , , , 1)
            If z = 0 Then Exit Sub
   
            If z > 15000 Then z = 15000
   
            If z > y - x + 1 Then
                MsgBox "You specified more numbers to return than " _
                        & "are possible in the range!"
                Exit Sub
            End If
   
            Randomize
   
            Cells(1, 1) =  Int((y - x + 1) * Rnd + x)
   
            For i = 2 To z
                Do
                    flag = False
                    Randomize
                    tempnum = Int((y - x + 1) * Rnd + x)
   
                    Set foundCell = Range("a1", _
                           Range("a1").End(xlDown).Address).Find(tempnum)
                    If Not (foundCell Is Nothing) Then
                        flag = True
                    End If
   
                Loop Until Not flag
   
                Cells(i, 1) =  tempnum
   
            Next
   
         End Sub 




2. Open a blank worksheet.



3. On the Tools menu, click Macro.
   
   In Microsoft Excel 97, on the Tools menu, point to Macro, and click Macros.



4. Click the Unique_Numbers macro, and then click Run.

REFERENCES

For additional information about getting help with Visual Basic for Applications, please see the following article in the Microsoft Knowledge Base:

Q163435 VBA: Programming Resources for Visual Basic for Applications

Additional query words: XL97

Keywords : kbprg kbdta kbdtacode PgmHowto KbVBA
Version : MACINTOSH:5.0,5.0a,98; WINDOWS:5.0,5.0c,7.0; winnt:5.0
Platform : MACINTOSH WINDOWS winnt
Issue type : kbhowto