Insertion Sort for a Numeric Array

Category:

Lists, Collections and Arrays

Type:

Snippets

Difficulty:

Intermediate

Author:

Intelligent Solutions Inc.

Version Compatibility:

More information:

This method uses the insertion sort algorithm to sort a numeric array. This algorithm is one of the simplest available, but there are better algorithms (to be posted on this site shortly) for longer lists.

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

Declarations:
' (None)

Code:

Public Function SortedArray(ByVal NumericArray As Variant) _
As Variant

'RETURNS Array, or vbEmpty if there's an error
'e.g., passed array contains elements that 
'can't be compared to each other, such as
'objects

'will work when elements are all numbers or single characters
'of the same case.

Dim iStartPoint As Integer, vTemp As Variant
Dim lItem As Long, lCtr As Long, lCtr2 As Long

Dim vVal As Variant
Dim vOrigArray As Variant

Dim vAns As Variant
Dim lNumSorted As Long
Dim lMax As Long

vAns = NumericArray
  
If Not IsArray(vAns) Then
    SortedArray = vbEmpty
    Exit Function
End If

On Error GoTo errorhandler
vOrigArray = vAns
iStartPoint = LBound(vAns)
lMax = UBound(vAns) - 1

lNumSorted = 0

For lItem = iStartPoint To lMax

vVal = vOrigArray(lItem + 1)
        
    For lCtr = iStartPoint To lNumSorted
      If vAns(lCtr) >= vVal Then Exit For
    Next
    
   For lCtr2 = lNumSorted To lCtr Step -1
      vAns(lCtr2 + 1) = vAns(lCtr2)
   Next
    
    'insert new item
    
     vAns(lCtr) = vVal
     lNumSorted = lNumSorted + 1
 Next
  
SortedArray = vAns
Exit Function

'because it's a variant
'people can pass objects or
'other types that can't be
'compared or sorted
errorhandler:
SortedArray = vbEmpty

Exit Function

End Function