Compare Two Arrays

This function compares the values of the first array with the values of the second array. If all values in the first array are present in the second array, regardless of the order of the values, the function returns a Boolean trUE. Otherwise, the function returns a FALSE value. It's important to understand that the second array could contain additional elements that are not in the first array, and the function would still return a TRUE value as long as all of the elements in the first array are included.

How It Works

The CompareArray object will store the result of the comparison. At the start of the function, this object is set to TRUE. Next, two ForAll loops are established, one for each array. Each element in the first array is then compared to all array elements in the second array. If ElementA is found in ArrayB, then the inner loop stops and the next value in ArrayA is compared. This prevents unnecessary looping in ArrayB when a match is found. If no match is found in ArrayB, then the CompareArrays object is set to FALSE, and the function exits.

Implementation

This function requires two arrays. After the arrays are compared, the function will return either a TRUE or FALSE value.

Function CompareArrays (ArrayA As Variant, ArrayB As Variant) As Boolean Dim FoundMatch As Boolean Dim ArrayMatch As Boolean CompareArrays = True Forall varElementA In ArrayA FoundMatch = False Forall varElementB In ArrayB If varElementA = varElementB Then FoundMatch = True Exit Forall End If End Forall If FoundMatch = False Then CompareArrays = False Exit Forall End If End Forall End Function

The following code illustrates the CompareArrays function. In this example, two arrays are passed to the LotusScript library function. A message box then displays either "All elements found" (see Figure 13.4) or "All elements not found" based on the result of the array comparison.

Sub Click(Source As Button) Dim TeamA (0 To 2) As String TeamA (0) = "Tom" TeamA (1) = "Henry" TeamA (2) = "Mark" Dim TeamB (0 To 2) As String TeamB (0) = "Mark" TeamB (1) = "Tom" TeamB (2) = "Henry" Msgbox Implode (TeamA, ", "), , "Team A" Msgbox Implode (TeamB, ", "), , "Team B" If CompareArrays( TeamA, TeamB) Then Msgbox "All elements found" Else Msgbox "All elements not found" End If End Sub

Figure 13.4. Compare two arrays

The array values passed to the CompareArrays function can also reference fields on a form provided that the arrays are of the same type (e.g., string or numbers). In other words, an array of strings will not compare to an array of numbers. To implement this solution, simply replace the references to TeamA and TeamB with document fields as illustrated next (where FIELDA and FIELDB represent fields on a form).

Dim w As NotesUIWorkspace Dim s As NotesSession Dim db As NotesDatabase Dim uidoc As NotesUIDocument Dim doc As NotesDocument Set w = New NotesUIWorkspace Set s = New NotesSession Set db = s.CurrentDatabase Set uidoc = w.CurrentDocument Set doc = uidoc.Document If CompareArrays(doc.FIELDA, doc.FIELDB) Then Msgbox "All elements found" Else Msgbox "all elements not found" End If