VB.Net/Language Basics/If

Материал из VB Эксперт
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If ElseIf Else End If Demo

<source lang="vbnet"> Imports System Public Class MainClass

   Shared Sub Main()
       "Declare and set a variable
       Dim intNumber As Integer = 27
       If intNumber = 1000 Then
           System.Console.WriteLine(""intNumber" is, indeed, 1000!")
       ElseIf intNumber = 27 Then
           System.Console.WriteLine(""intNumber" is 27!")
       Else
           System.Console.WriteLine(""intNumber" is not 1000!")
       End If
   End Sub

End Class

      </source>


If Then Else Demo

<source lang="vbnet"> Imports System Public Class MainClass

   Shared Sub Main()
       "Declare variables
       Dim strName1 As String, strName2 As String
       "Get the names
       strName1 = "Sydney"
       strName2 = "Vancouver"
       "Is one of the names Sydney?
       If strName1 = "Sydney" Or strName2 = "Sydney" Then
           System.Console.WriteLine("One of the names is Sydney.")
       Else
           System.Console.WriteLine("Neither of the names is Sydney.")
       End If
   End Sub

End Class

      </source>


If then else if

<source lang="vbnet"> Imports System public class MainClass

   Shared Sub Main()
      Dim valueOne As Integer = 10
      Dim valueTwo As Integer = 20
      Dim valueThree As Integer = 30
      If valueOne > valueTwo Then
         Console.WriteLine( _
             "ValueOne: {0} larger than ValueTwo: {1}", valueOne, valueTwo)
      Else
         Console.WriteLine( _
            "Nope, ValueOne: {0} is NOT larger than valueTwo: {1}", _
             valueOne, valueTwo)
      End If
   End Sub

End Class


      </source>


If with Else

<source lang="vbnet"> Imports System Public Class MainClass

   Shared Sub Main(ByVal args As String())
      Dim valueOne As Integer = 10
      Dim valueTwo As Integer = 20
      Dim valueThree As Integer = 30
      If valueOne > valueTwo Then
         Console.WriteLine("ValueOne: {0} larger than ValueTwo: {1}", valueOne, valueTwo)
      Else
         Console.WriteLine("Nope, ValueOne: {0} is NOT larger than valueTwo: {1}", valueOne, valueTwo)
      End If
   End Sub

End Class

      </source>


Nested If

<source lang="vbnet"> Imports System public class MainClass

   Shared Sub Main()
      Dim temp As Integer = 32
      If temp <= 32 Then
         Console.WriteLine("temp <= 32")
         If temp = 32 Then
            Console.WriteLine("temp = 32")
         Else
            Console.WriteLine("Temp: {0}", temp)
         End If
      End If
   End Sub

End Class


      </source>


Simple If Then

<source lang="vbnet"> Imports System Public Class MainClass

   Shared Sub Main()
       Dim intNumber As Integer = 27
       If intNumber = 27 Then
           System.Console.WriteLine(""intNumber" is, indeed, 27!")
       End If
   End Sub

End Class

      </source>


Use function in if statement

<source lang="vbnet"> Imports System public class MainClass

   Shared Sub Main()
        Dim x As Integer = 7
        If IsSmaller(x, 8) OrElse IsBigger(x, 12) Then
            Console.WriteLine("x < 8 OrElse x > 12")
        Else
            Console.WriteLine("Not True that x < 8 OrElse x > 12")
        End If
   End Sub
   Shared Function IsBigger(ByVal firstVal As Integer,ByVal secondVal As Integer) _
        As Boolean
        If firstVal > secondVal Then
            Return True
        Else
            Return False
        End If
    End Function
   Shared Function IsSmaller(ByVal firstVal As Integer,ByVal secondVal As Integer) _
        As Boolean
        If firstVal < secondVal Then
            Return True
        Else
            Return False
        End If
    End Function

End Class


      </source>