vb System.Array.Exists<T>类(方法)实例源码

Module Example
    Public Sub Main()
        Dim planets() As String = {"Mercury", "Venus",
                                    "Earth", "Mars", "Jupiter",
                                    "Saturn", "Uranus", "Neptune"}

        Console.WriteLine("One or more planets begin with 'M': {0}",
            Array.Exists(planets, Function(element)
                                      Return element.StartsWith("M")
                                  End Function))

        Console.WriteLine("One or more planets begin with 'T': {0}",
            Array.Exists(planets, Function(element)
                                      Return element.StartsWith("T")
                                  End Function))

        Console.WriteLine("Is Pluto one of the planets? {0}",
            Array.Exists(planets, Function(element)
                                      Return element.Equals("Pluto")
                                  End Function))

    End Sub
End Module

Module Example
   Public Sub Main()
      Dim names() As String = { "Adam", "Adel", "Bridgette", "Carla",
                                "Charles", "Daniel", "Elaine", "Frances",
                                "George", "Gillian", "Henry", "Irving",
                                "James", "Janae", "Lawrence", "Miguel",
                                "Nicole", "Oliver", "Paula", "Robert",
                                "Stephen", "Thomas", "Vanessa",
                                "Veronica", "Wilberforce" }
      Dim charsToFind() As Char = { "A"c, "K"c, "W"c, "Z"c }
      
      For Each charToFind In charsToFind
         Console.WriteLine("One or more names begin with '{0}': {1}",
                           charToFind,
                           Array.Exists(names, AddressOf (New StringSearcher(charToFind)).StartsWith))
      Next
   End Sub
   
End Module

Public Class StringSearcher
   Dim firstChar As Char
   
   Public Sub New(firstChar As Char)
      Me.firstChar = Char.ToUpper(firstChar)
   End Sub
   
   Public Function StartsWith(s As String) As Boolean
      If String.IsNullOrEmpty(s) Then Return False
      
      If s.Substring(0, 1).ToUpper = firstChar Then
         Return True
      Else
         Return False
      End If
   End Function
End Class

Module Example
   Public Sub Main()
      Dim names() As String = { "Adam", "Adel", "Bridgette", "Carla",
                                "Charles", "Daniel", "Elaine", "Frances",
                                "George", "Gillian", "Henry", "Irving",
                                "James", "Janae", "Lawrence", "Miguel",
                                "Nicole", "Oliver", "Paula", "Robert",
                                "Stephen", "Thomas", "Vanessa",
                                "Veronica", "Wilberforce" }
      Dim charsToFind() As Char = { "A"c, "K"c, "W"c, "Z"c }

      For Each charToFind In charsToFind
         Console.WriteLine("One or more names begin with '{0}': {1}",
                           charToFind,
                           Array.Exists(names, Function(s)
                                                  If String.IsNullOrEmpty(s) Then Return False

                                                  If s.Substring(0, 1).ToUpper = charToFind Then
                                                     Return True
                                                  Else
                                                     Return False
                                                  End If
                                               End Function ))
      Next
   End Sub
End Module