Binaryworld - PluralToSingular - Converting the input word from plural to singular ... [ VB.net -> String ]

' Convert the input word from plural to singular
Function PluralToSingular(ByVal plural As String) As String
  ' convert to lowercase for easier comparison
  Dim lower As String = plural.ToLower()
  Dim res As String

  ' rule out a few exceptions
  If lower = "feet" Then
    res = "Foot"
  ElseIf lower = "geese" Then
    res = "Goose"
  ElseIf lower = "men" Then
    res = "Man"
  ElseIf lower = "women" Then
    res = "Woman"
  ElseIf lower = "criteria" Then
    res = "Criterion"

    ' plural uses "ies" if word ends with "y" preceeded by a non-vowel
  ElseIf lower.EndsWith("ies") AndAlso "aeiou".IndexOf(lower.Substring _
    (lower.Length - 4, 1)) < 0 Then
    res = plural.Substring(0, plural.Length - 3) + "y"
  Else
    res = plural.Substring(0, plural.Length - 1)
  End If

  ' the result must preserve the original word's capitalization
  If plural = lower Then
    Return res.ToLower() ' it was an all-lowercase word
  ElseIf plural = plural.ToUpper() Then
    Return res.ToUpper()  ' it was an all-uppercase word
  Else
    Return res  ' return whatever is in "res"
  End If
End Function