VB.Net Tutorial/Statements/Select

Материал из VB Эксперт
Версия от 15:53, 26 мая 2010; Admin (обсуждение | вклад) (1 версия)
(разн.) ← Предыдущая | Текущая версия (разн.) | Следующая → (разн.)
Перейти к: навигация, поиск

Select Case statement with Integer and exact value

<source lang="vbnet">Option Strict On

Imports System
Module Module1
   Sub Main( )
      Dim targetInteger As Integer = 15
      Select Case targetInteger
         Case 5
            Console.WriteLine("5")
         Case 10
            Console.WriteLine("10")
         Case 15
            Console.WriteLine("15!")
         Case Else
            Console.WriteLine("Value not found")
      End Select
   End Sub "Main
End Module</source>
15!

Select Case statement with range Integer value

<source lang="vbnet">Option Strict On

Imports System
Module Module1
   Sub Main( )
      Dim targetInteger As Integer = 7
      Select Case targetInteger
         Case Is < 10
            Console.WriteLine("Less than 10")
         Case 10 To 14
            Console.WriteLine("10-14")
         Case 15
            Console.WriteLine("15!")
         Case Else
            Console.WriteLine("Value not found")
      End Select
   End Sub "Main
End Module</source>
Less than 10

Select Case statement with String range value

<source lang="vbnet">Option Strict On

Imports System
Module Module1
   Sub Main( )
      Dim target As String = "M"
      Select Case target
         Case "A" To "L"
            Console.WriteLine("A To L executed")
         Case "L" To "Z"
            Console.WriteLine("L To Z executed")
         Case Else
            Console.WriteLine("Else executed")
      End Select
   End Sub "Main
End Module</source>
L To Z executed

Select Now.DayOfWeek

<source lang="vbnet">public class Test

  public Shared Sub Main
       Dim strMessage As String
       Select Case Now.DayOfWeek
           Case DayOfWeek.Monday
               strMessage = "Have a nice week."
           Case DayOfWeek.Friday
               strMessage = "Have a nice weekend."
           Case Else
               strMessage = "Welcome back!"
       End Select
       Console.WriteLine(strMessage)
  End Sub

End class</source>

Have a nice weekend.

Specify several values in one Case statement

<source lang="vbnet">public class Test

  public Shared Sub Main
       Select Case "Bird"
           Case "Bird"
               Console.WriteLine("This animal has 2 legs.")
           Case "Horse", "Dog", "Cat"
               Console.WriteLine("This animal has 4 legs.")
           Case "Snake"
               Console.WriteLine("This animal has no legs.")
           Case "Centipede"
               Console.WriteLine("This animal has 100 legs.")
           Case Else
               Console.WriteLine("You did not select from the list!")
       End Select
  End Sub

End Class</source>

This animal has 2 legs.

Use both range and fix value in Select statement

<source lang="vbnet">Module Module1

   Sub Main()
       Dim intInput As Integer = 12
       
       
       Select Case intInput
           Case 1
               Console.WriteLine("Thank you for the 1.")
           Case 2 To 5
               Console.WriteLine("Your value was 2, 3, 4, or 5")
           Case Is > 5
               Console.WriteLine("That was greater than 5.")
           Case Else
               Console.WriteLine("Sorry, I can"t deal with that.")
       End Select
   End Sub

End Module</source>

That was greater than 5.

Using Select Case structure

<source lang="vbnet">Module Tester

  Sub Main()
     Dim grade As Integer = 89  
     Dim aCount As Integer = 0 
     Dim bCount As Integer = 0 
     Dim cCount As Integer = 0 
     Dim dCount As Integer = 0 
     Dim fCount As Integer = 0 
     Select Case grade    
        Case 100          
           Console.WriteLine("Perfect Score!" & vbCrLf & "Letter grade: A" & vbCrLf)
           aCount += 1
        Case 90 To 99     
           Console.WriteLine("Letter Grade: A" & vbCrLf)
           aCount += 1
        Case 80 To 89     
           Console.WriteLine("Letter Grade: B" & vbCrLf)
           bCount += 1
        Case 70 To 79     
           Console.WriteLine("Letter Grade: C" & vbCrLf)
           cCount += 1
        Case 60 To 69     
           Console.WriteLine("Letter Grade: D" & vbCrLf)
           dCount += 1
        Case 0, 10 To 59
           Console.WriteLine("Letter Grade: F" & vbCrLf)
           fCount += 1
        Case Else
           Console.WriteLine("Invalid Input. " & _
              "Please enter a valid grade." & vbCrLf)
     End Select
  End Sub  

End Module</source>

Letter Grade: B