VB.Net/Language Basics/For Each — различия между версиями

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м (1 версия)
 
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Текущая версия на 12:42, 26 мая 2010

Exit a For Each loop

Imports System
Imports System.Collections
Public Class MainClass
    
    Shared Sub Main(ByVal args As String())
        Dim employees As New Collection
        employees.Add(New Employee("A"))
        employees.Add(New Manager("B"))
        employees.Add(New Employee("C"))
        Dim a_manager As Manager = Nothing
        For Each emp2 As Employee In employees
            If TypeOf emp2 Is Manager Then
                a_manager = CType(emp2, Manager)
                Exit For
            End If
        Next emp2
        Console.WriteLine("Manager: " & a_manager.Name)
    End Sub
End Class

Public Class Employee
    Public Name As String
    Public Sub New(ByVal new_name As String)
        Name = new_name
    End Sub
    Public Overridable Function IsManager() As Boolean
        Return False
    End Function
End Class
Public Class Customer
    Public Name As String
    Public Sub New(ByVal new_name As String)
        Name = new_name
    End Sub
End Class
Public Class Manager
    Inherits Employee
    Public Sub New(ByVal new_name As String)
        MyBase.new(new_name)
    End Sub
    Public Overrides Function IsManager() As Boolean
        Return True
    End Function
End Class


Loop through an Array

Imports System
Public Class MainClass
    Shared Sub Main()
        "Declare an array
        Dim strFriends(4) As String
        "Populate the array
        strFriends(0) = "R"
        strFriends(1) = "B"
        strFriends(2) = "S"
        strFriends(3) = "S"
        strFriends(4) = "K"
        "Enumerate the array
        For Each strName As String In strFriends
            "Add the array item to the list
            System.Console.WriteLine(strName)
        Next
    End Sub
End Class


Use For Each to Loop an Array

Imports System
Public Class MainClass
    Shared Sub Main(ByVal args As String())
        Dim friends() As String = {"A", "B", "C","D", "E"}

        Dim friendName As String
        For Each friendName In friends
            Console.WriteLine(friendName)
        Next
    End Sub
    
End Class