Create and randomly shuffle contents of an array in one function call

Category:

Miscellaneous

Type:

Snippets

Difficulty:

Beginning

Author:

Branimir Bajt

Version Compatibility: Visual Basic 6, Visual Basic 5

Instructions: Copy the declarations and code below and paste directly into your VB project.

Declarations:
'// (none)

Code:

Public Function GetRndArray(ByVal Min As Long, ByVal Max As Long, Optional ByVal NumSwap As Long = 1) As Long()
    '// Create and randomly shuffle contents of an array
    '//
    Dim n As Long, lTimes As Long, lRnd As Long, lTmp As Long
    '//
    '// Create array and populate it with numbers ...
    ReDim lArray(Min To Max) As Long
    '//
    For n = Min To Max
        lArray(n) = n '// Assign number ...
    Next n
    '//
    Call Randomize(Timer) '// (Re)Initialize random numbers generator ...
    '//
    '// (Re)Shuffle lArray() NumSwap times ...
    '// If NumSwap is 0 (zero), array will not be shuffled ...
    For lTimes = 1 To NumSwap
        For n = Min To Max
            lRnd = Int(Rnd * (Max - Min + 1) + Min) '//
            lTmp = lArray(n) '// assign original value to temp variable ...
            '//
            lArray(n) = lArray(lRnd) '// Set array element lArray(n) equal to random array element lRnd ...
            lArray(lRnd) = lTmp '// Set array element lRnd to old value of array element i stored as lTmp ...
        Next n
    Next lTimes
    '//
    GetRndArray = lArray
End Function