Reference Page: Comparison Rules

Automatic Comparison Rules

Relationship: One-to-One / Rule: Is Value Less

Definitions

Supported data types: String, Number, Date

Comparison of values of different data types always returns False.
Comparison of values of unsupported data types always returns False.

Data type: String

Strings are compared based on total length and encoding of each character.

A string of shorter length is always considered lesser. (Updated 2010/07/20, see comments section)

Comparison of two strings is performed character by character up to the first character that differs. The string with the lesser character in that position is considered lesser.

Data type: Number

A lesser value is considered lesser than a bigger one. All negative numbers are less than zero and all positive numbers. Thus, -1 is less than 100; -100 is less than -1.

The floating-point value NaN (not a number) is greater than any other numeric value and is equal to itself.

Data type: Date

Date/time values are compared per component values: Year, Month, Day, Hour, Second.
A later date is considered greater than an earlier one. A date with a greater month but lesser year is considered less, and so forth.

Implementation

Public Function isValueLess(ByVal sActualValue, ByVal sExpectedValue, ByVal sFormat)
 If Not isSameFormat(sActualValue, sExpectedValue, sFormat) Then
 isValueLess = False
 Exit Function
 End If
 Select Case UCase(sFormat)
 Case "NUMBER"
 If CDbl(sActualValue) < CDbl(sExpectedValue) Then
 isValueLess = True
 Else
 isValueLess = False
 End If
 Case "DATE" 
 If DateDiff("s", CDate(sActualValue), CDate(sExpectedValue)) > 0 Then
 isValueLess = True
 Else
 isValueLess = False
 End If
 Case "STRING"
 If StrComp(sActualValue, sExpectedValue, vbBinaryCompare) = -1 Then
 isValueLess = True
 Else
 isValueLess = False
 End If
 Case Else 
 isValueLess = False
 End Select
End Function

Test Code

 Log.Message("1-1 Comparison: isValueLess")
 boolRC = isValueLess("aaaazzzz", "zzzzaaaa", "String")
 If Not boolRC Then
 Log.Error("isValueLess failed")
 End If
 boolRC = isValueLess("ab", "abc", "String")
 If Not boolRC Then
 Log.Error("isValueLess failed")
 End If
 boolRC = isValueLess("ab ", "abc", "String")
 If Not boolRC Then
 Log.Error("isValueLess failed")
 End If
 boolRC = isValueLess(0, 1, "Number")
 If Not boolRC Then
 Log.Error("isValueLess failed")
 End If
 boolRC = isValueLess(0, dblNearlyZero, "Number")
 If Not boolRC Then
 Log.Error("isValueLess failed")
 End If
 boolRC = isValueLess(-1, 0, "Number")
 If Not boolRC Then
 Log.Error("isValueLess failed")
 End If
 boolRC = isValueLess(-10, -1, "Number")
 If Not boolRC Then
 Log.Error("isValueLess failed")
 End If
 sValue1 = CDate("01/01/01")
 sValue2 = CDate("1/1/2002")
 boolRC = isValueLess(sValue1, sValue2, "DATE")
 If Not boolRC Then
 Log.Error("isValueLess failed")
 End If
 sValue1 = CDate("31/12/2050")
 sValue2 = CDate("1/1/2050")
 boolRC = isValueLess(sValue1, sValue2, "DATE")
 If boolRC Then
 Log.Error("isValueLess failed")
 End If