Microsoft KB Archive/213290

= XL2000: How to Create Unique Random Integers Between Two Numbers =

Article ID: 213290

Article Last Modified on 11/23/2006

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APPLIES TO


 * Microsoft Excel 2000 Standard Edition

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This article was previously published under Q213290





SUMMARY
In Microsoft Excel, you can create a Microsoft Visual Basic Sub procedure (macro) to create a list of unique (non-repeating) random integers between two other numbers.

This articles describes a sample macro that prompts the user for a starting integer and an ending integer, prompts the user to input the number of random numbers to generate, and then generates a list of unique integers on the active worksheet.



MORE INFORMATION
Microsoft provides programming examples for illustration only, without warranty either expressed or implied, including, but not limited to, the implied warranties of merchantability and/or fitness for a particular purpose. This article assumes that you are familiar with the programming language being demonstrated and the tools used to create and debug procedures. Microsoft support professionals 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 needs. If you have limited programming experience, you may want to contact a Microsoft Certified Partner or the Microsoft fee-based consulting line at (800) 936-5200. For more information about Microsoft Certified Partners, please visit the following Microsoft Web site:

https://partner.microsoft.com/global/30000104

For more information about the support options that are available and about how to contact Microsoft, visit the following Microsoft Web site:

http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

To create and run the macro described in the "Summary" section, follow these steps:  Start Excel, and then Press ALT+F11 to start the Visual Basic editor. On the Insert menu, click Module.  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  Press ALT+F11 to return to Excel. On the Tools menu, point to Macro, and then click Macros. In the Macro name list, click Unique_Numbers, and then click Run.</li></ol>

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